drm/amd/display: Add ETW log to dmub_psr_get_state

[Why]
GPINT commands have the lowest priority in DMCUB, so it's possible
that the command isn't processed in time.

[How]
Add a log to help identify this case.

Reviewed-by: Koo Anthony <Anthony.Koo@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>