drm/amd/display: change fastboot timing validation

[Why]
VBIOS light up eDP with 6bpc but driver use 8bpc without
disable valid stream then re-enable valid stream. Some
panels can't runtime change color depth.

[How]
Change fastboot timing validation function. Not only check
LANE_COUNT, LINK_RATE...etc

Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Paul Hsieh <paul.hsieh@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>