drm/amd/display: Add additional pstate registers to HW state query

[WHY]
These registers would be useful to know when debugging pstate issues.

[HOW]
Add additional registers to hw state query.

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Sung Lee <sunglee@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>