msm: mdss: reset DSI LANE control register during initialization

Sometimes during suspend due to some shared regulator, if DSI PHY
was not turned off properly, then DSI LANE control register might
store some stale values during resume and this might cause side
effects on panel during initialization sequence. So reset the DSI
lane control register during DSI host initialization.

Change-Id: Ib87281cc1346d88a83e7e26f7dc4951a0798276b
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>