drm/exynos: hdmi: don't leak enable HDMI_EN regulator if probe fails

drm/exynos: hdmi: don't leak enable HDMI_EN regulator if probe fails

Move enabling and disabling HDMI_EN optional regulator to probe() function
to keep track on the regulator status. This fixes following warning if
probe() fails (for example when I2C DDC adapter cannot be yet gathered
due to the missing driver). This fixes following warning observed on
Arndale5250 board with multi_v7_defconfig:

[drm] Failed to get ddc i2c adapter by node
------------[ cut here ]------------
WARNING: CPU: 0 PID: 214 at drivers/regulator/core.c:2051 _regulator_put+0x16c/0x184
Modules linked in: ...
CPU: 0 PID: 214 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200219-00040-g38af1dfafdbb #7570
Hardware name: Samsung Exynos (Flattened Device Tree)
[<c0312258>] (unwind_backtrace) from [<c030cc10>] (show_stack+0x10/0x14)
[<c030cc10>] (show_stack) from [<c0f0d3a0>] (dump_stack+0xcc/0xe0)
[<c0f0d3a0>] (dump_stack) from [<c0346a58>] (__warn+0xe0/0xf8)
[<c0346a58>] (__warn) from [<c0346b20>] (warn_slowpath_fmt+0xb0/0xb8)
[<c0346b20>] (warn_slowpath_fmt) from [<c0893f58>] (_regulator_put+0x16c/0x184)
[<c0893f58>] (_regulator_put) from [<c0893f8c>] (regulator_put+0x1c/0x2c)
[<c0893f8c>] (regulator_put) from [<c09b2664>] (release_nodes+0x17c/0x200)
[<c09b2664>] (release_nodes) from [<c09aebe8>] (really_probe+0x10c/0x350)
[<c09aebe8>] (really_probe) from [<c09aefa8>] (driver_probe_device+0x60/0x1a0)
[<c09aefa8>] (driver_probe_device) from [<c09af288>] (device_driver_attach+0x58/0x60)
[<c09af288>] (device_driver_attach) from [<c09af310>] (__driver_attach+0x80/0xbc)
[<c09af310>] (__driver_attach) from [<c09ace34>] (bus_for_each_dev+0x68/0xb4)
[<c09ace34>] (bus_for_each_dev) from [<c09ae00c>] (bus_add_driver+0x130/0x1e8)
[<c09ae00c>] (bus_add_driver) from [<c09afd98>] (driver_register+0x78/0x110)
[<c09afd98>] (driver_register) from [<bf139558>] (exynos_drm_init+0xe8/0x11c [exynosdrm])
[<bf139558>] (exynos_drm_init [exynosdrm]) from [<c0302fa8>] (do_one_initcall+0x50/0x220)
[<c0302fa8>] (do_one_initcall) from [<c03dc02c>] (do_init_module+0x60/0x210)
[<c03dc02c>] (do_init_module) from [<c03daf44>] (load_module+0x1c0c/0x2310)
[<c03daf44>] (load_module) from [<c03db85c>] (sys_finit_module+0xac/0xbc)
[<c03db85c>] (sys_finit_module) from [<c0301000>] (ret_fast_syscall+0x0/0x54)
Exception stack(0xecca3fa8 to 0xecca3ff0)
...
---[ end trace 276c91214635905c ]---

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>