mipi_novatek: Add back display_on usage
video: msm: Fix initial state of LCD backlight

* For devices which use the LCD backlight we need to actually call the
* function which sets the brightness after initializing it in the probe.

Change-Id: Id6b7c0de3cd31181394c56c7f6061bca9defd861
Revert "Fix panel power on"

This reverts commit 051906ee48e65ef8a1797c09c69f5ddfa8382040.
mipi_novatek: Use tx for display_on cmds_