ARM: dts: msm: fix screen display shift issue for ssd2080m

Change "vertical back porch"/"vertical front porch" and
"vertical pulse width" to adjust ssd2080m requirement,
otherwise screen will shift to bottom a bit.

Signed-off-by: Ray Zhang <rayzhang@codeaurora.org>
Change-Id: Id3d1f19dc036554c40308b13dc668938460463a8