drm/amd/powerplay: fix checking gfxoff status for rn

drm/amd/powerplay: fix checking gfxoff status for rn

For renoir, it should use mmSMUIO_GFX_MISC_CNTL to check
gfxoff status. For the first time to enter gfxoff status,
it maybe takes about one second more. So just set the max
timeout to 5s.

GFXOFF_STATUS(bits 2:1)'s description is below:
0=GFXOFF(default).
1=Transition out of GFX State.
2=Not in GFXOFF.
3=Transition into GFXOFF.

Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>