GFX-display: Suboptimal sequence in mdfld_dsi_pr2_power_on

GFX-display:  Suboptimal sequence in mdfld_dsi_pr2_power_on

BZ: 38884

optimize the sequence of TURN_ON
because according spec, after TURN_ON need wait 100ms.
after exit sleep 120ms is needed.

here try to  optimize the sequence to reduce the wait time

Change-Id: I0f81d52d294895e5c83672ecff436bf3de33d53a
Signed-off-by: Ke Ai <ke.ai@intel.com>
Reviewed-on: http://android.intel.com:8080/52315
Reviewed-by: Xu, Randy <randy.xu@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>