drm/amd/display: Fix runtime errors for diagnostic tests

drm/amd/display: Fix runtime errors for diagnostic tests

1) Rename and make public definition of input CSC matrix struct.
2) Make wm_read_state() function an interface of hubbub, and check
   if watermark registers exist before read/write to them.
3) Check if OTG_INTERLACE_CONTROL register exists before updating
4) Add dummy functions for set_input/output_transfer function to avoid
   errors due to differences in CM registers.
5) Added missing register field definition in header file

Signed-off-by: Eric Bernstein <eric.bernstein@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>