drm/amd/display: Get replay info from VSDB

We need to make sure that the panel supports replay.

This info is inside the amd vsdb (vendor specific data block). Create a
function to parse the block and read the replay_mode bit.

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>