MLK-19252-7 drm/bridge: sec-dsim: workaround for 720p@60Hz on 4 lanes

MLK-19252-7 drm/bridge: sec-dsim: workaround for 720p@60Hz on 4 lanes

For the CEA standard mode '1280x720@60Hz', the standard HFP value
is not suitable for the DSI peripheral which works with Non-burst
with Sync Pulse mode with 4 data lanes enabled. And this commit is
a workaround to plus 2 to the original HFP value to make this case
can display correctly.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>
(cherry picked from commit 8b39ff24f89c5a9d21459ab5af47259060185b0a)
(cherry picked from commit 56c91a7ee40f866ae770b2f20b3ea623c6c2f0cc)
(cherry picked from commit cff6ad221228f69728c689a8ca7359eaa642573c)