lcdc_ld9040: add additional mutex protection

Change-Id: Ifa7be9a321e4b63fc1a5dda968db177ffb73be1c
ld9040: fix late resume

* added lcd regulator checks before late resume calls lcd init
* fixes upside-down lockscreen upon resume
* fixes lcd not waking upon resume

Change-Id: Ia152c3b61afff14404488ed8b46e7bf777728f12