[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: Rodrigo Siqueira <Rodrigo.Siqueira@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>