drm/i915: Do not read PSR2 register in transcoders without PSR2

drm/i915: Do not read PSR2 register in transcoders without PSR2

This fix unclaimed access warnings:

[  245.525788] ------------[ cut here ]------------
[  245.525884] Unclaimed read from register 0x62900
[  245.526154] WARNING: CPU: 0 PID: 1234 at drivers/gpu/drm/i915/intel_uncore.c:1100 __unclaimed_reg_debug+0x40/0x50 [i915]
[  245.526160] Modules linked in: i915 x86_pkg_temp_thermal ax88179_178a coretemp usbnet crct10dif_pclmul mii crc32_pclmul ghash_clmulni_intel e1000e [last unloaded: i915]
[  245.526191] CPU: 0 PID: 1234 Comm: kms_fullmodeset Not tainted 5.1.0-rc6+ #915
[  245.526197] Hardware name: Intel Corporation Tiger Lake Client Platform/TigerLake U DDR4 SODIMM RVP, BIOS TGLSFWR1.D00.2081.A10.1904182155 04/18/2019
[  245.526273] RIP: 0010:__unclaimed_reg_debug+0x40/0x50 [i915]
[  245.526281] Code: 74 05 5b 5d 41 5c c3 45 84 e4 48 c7 c0 76 97 21 a0 48 c7 c6 6c 97 21 a0 89 ea 48 0f 44 f0 48 c7 c7 7f 97 21 a0 e8 4f 1e fe e0 <0f> 0b 83 2d 6f d9 1c 00 01 5b 5d 41 5c c3 66 90 41 57 41 56 41 55
[  245.526288] RSP: 0018:ffffc900006bf7d8 EFLAGS: 00010086
[  245.526297] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  245.526304] RDX: 0000000000000007 RSI: 0000000000000000 RDI: 00000000ffffffff
[  245.526310] RBP: 0000000000061900 R08: 0000000000000000 R09: 0000000000000001
[  245.526317] R10: 0000000000000006 R11: 0000000000000000 R12: 0000000000000001
[  245.526324] R13: 0000000000000000 R14: ffff8882914f0d58 R15: 0000000000000206
[  245.526332] FS:  00007fed2a3c39c0(0000) GS:ffff8882a8600000(0000) knlGS:0000000000000000
[  245.526340] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  245.526347] CR2: 00007fed28dff000 CR3: 00000002a086c006 CR4: 0000000000760ef0
[  245.526354] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  245.526361] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  245.526367] PKRU: 55555554
[  245.526373] Call Trace:
[  245.526454]  gen11_fwtable_read32+0x219/0x250 [i915]
[  245.526576]  intel_psr_activate+0x57/0x400 [i915]
[  245.526697]  intel_psr_enable_locked+0x367/0x4b0 [i915]
[  245.526828]  intel_psr_enable+0xa4/0xd0 [i915]
[  245.526946]  intel_enable_ddi+0x127/0x2f0 [i915]
[  245.527075]  intel_encoders_enable.isra.79+0x62/0x90 [i915]
[  245.527202]  haswell_crtc_enable+0x2a2/0x850 [i915]
[  245.527337]  intel_update_crtc+0x51/0x360 [i915]
[  245.527466]  skl_update_crtcs+0x26c/0x300 [i915]
[  245.527603]  intel_atomic_commit_tail+0x3e5/0x13c0 [i915]
[  245.527757]  intel_atomic_commit+0x24d/0x2d0 [i915]
[  245.527782]  drm_atomic_helper_set_config+0x7b/0x90
[  245.527799]  drm_mode_setcrtc+0x1b4/0x6f0
[  245.527856]  ? drm_mode_getcrtc+0x180/0x180
[  245.527867]  drm_ioctl_kernel+0xad/0xf0
[  245.527886]  drm_ioctl+0x2f4/0x3b0
[  245.527902]  ? drm_mode_getcrtc+0x180/0x180
[  245.527935]  ? rcu_read_lock_sched_held+0x6f/0x80
[  245.527956]  do_vfs_ioctl+0xa0/0x6d0
[  245.527970]  ? __task_pid_nr_ns+0xb6/0x200
[  245.527991]  ksys_ioctl+0x35/0x70
[  245.528009]  __x64_sys_ioctl+0x11/0x20
[  245.528020]  do_syscall_64+0x55/0x180
[  245.528034]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  245.528042] RIP: 0033:0x7fed2cc7c3c7
[  245.528050] Code: 00 00 90 48 8b 05 c9 3a 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 99 3a 0d 00 f7 d8 64 89 01 48
[  245.528057] RSP: 002b:00007ffe36944378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  245.528067] RAX: ffffffffffffffda RBX: 00007ffe369443b0 RCX: 00007fed2cc7c3c7
[  245.528074] RDX: 00007ffe369443b0 RSI: 00000000c06864a2 RDI: 0000000000000003
[  245.528081] RBP: 00007ffe369443b0 R08: 0000000000000000 R09: 0000564c0173ae98
[  245.528088] R10: 0000564c0173aeb8 R11: 0000000000000246 R12: 00000000c06864a2
[  245.528095] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
[  245.528128] irq event stamp: 140866
[  245.528138] hardirqs last  enabled at (140865): [<ffffffff819a63dc>] _raw_spin_unlock_irqrestore+0x4c/0x60
[  245.528148] hardirqs last disabled at (140866): [<ffffffff819a624d>] _raw_spin_lock_irqsave+0xd/0x50
[  245.528158] softirqs last  enabled at (140860): [<ffffffff81c0038c>] __do_softirq+0x38c/0x499
[  245.528170] softirqs last disabled at (140853): [<ffffffff810b4a09>] irq_exit+0xa9/0xc0
[  245.528247] WARNING: CPU: 0 PID: 1234 at drivers/gpu/drm/i915/intel_uncore.c:1100 __unclaimed_reg_debug+0x40/0x50 [i915]
[  245.528254] ---[ end trace 366069676e98a410 ]---

Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190823082055.5992-7-lucas.demarchi@intel.com