drm/amd/display: Enable copying of bounding box data from VBIOS DMUB

Allocate some memory, send the address in chunks to dmub, and finally
ask it to copy the bounding box data into the newly allocated memory.

Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>