drm/amd/display: Replay + IPS + ABM in Full Screen VPB

[Why]
Because ABM will wait VStart to start getting histogram data,
 it will cause we can't enter IPS while full screnn video playing.

[How]
Modify the panel refresh rate to the maximun multiple of current
 refresh rate.

Reviewed-by: Dennis Chan <dennis.chan@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: ChunTao Tso <chuntao.tso@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>