drm/amd/display: Detect panel type from VSDB

drm/amd/display: Detect panel type from VSDB

[Why]
The AMD VSDB contains two bits that indicate the type of panel connected.
This can be useful for policy decisions based upon panel technology.

[How]
Read the bits for the panel type when parsing VSDB and store them in
the dc_link.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Matthew Stewart <matthew.stewart2@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>