drm/amd/display: Tune min clk values for MPO for RV

[Why]
Incorrect values were resulting in flash lines
when MPO was enabled and system was left idle.

[How]
Increase min clk values only when MPO is enabled
and display is active to not affect S3 power.

Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>