msm: display: Adjust video timing generator parameters for 8930 EVT device.

This change adjusts the video timing generator parameters to properly configure
porch values for the panel.

Change-Id: I920646f1edbf4fe0043336dd0e2914f0302be2d8
Signed-off-by: Sangani Suryanarayana Raju <csuryan@codeaurora.org>