drm/amd/display: Add extra logging for HUBP and OTG

[Description]
Add extra logging for DCSURF_FLIP_CNTL, DCHUBP_CNTL,
OTG_MASTER_EN, and OTG_DOUBLE_BUFFER_CONTROL for more
debuggability for a system crash.

Reviewed-by: Samson Tam <samson.tam@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>