drm/amd/display: Add a buffer for boot time crc

drm/amd/display: Add a buffer for boot time crc

[Why]
We need to reserve a memory buffer for boot time crc test
during resume.

[How]
Create a buffer during boot up and send the buffer info to
DMUB.

Reviewed-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Chuanyu Tseng <chuanyu.tseng@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>