Try to get the 'video-mode' property from dtb to guide the required video mode configuration. The possible video modes are: 0. Burst mode 1. Non-burst mode with sync event 2. Non-burst mode with sync pulse Signed-off-by: Fancy Fang <chen.fang@nxp.com> (cherry picked from commit e920436e2174d72eac28f0fb09f1fcdc68add9d9)