drm/msm/dsi-staging: fix ulps during suspend for video mode

Currently DSI driver is only considering command mode panel
for getting the number of data lanes enabled, while waiting
for lanes to be idle. So in video mode the wait is failing
because of mismatch in number of data lanes. Also when
coming out of ulps in suspend we should not configure the
DSI controller twice, which may put the DSI HW in bad state.
This change fixes the same for ulps during suspend feature.

Change-Id: I090e7d726759a8317dee7941c1067207c986b98b
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>