drm/amd/display: Add more DC HW state info to underflow logging

drm/amd/display: Add more DC HW state info to underflow logging

[Why]
Debugging underflow issues frequently requires knowing the
HW state at the time of underflow. To enable capturing this
HW state information, interface functions are needed for the
various DC HW blocks.

[How]
This change adds the interface functions to read HW state for
the following DC HW blocks:
- HUBBUB
- HUBP
- DPP
- MPC
- OPP
- DSC
- OPTC
- DCCG

Reviewed-by: George Shen <george.shen@amd.com>
Signed-off-by: Karen Chen <Karen.Chen@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>