Revert "Revert "msm_fb: display: Add new panel_mutex""

This reverts commit 1fb885a530b7d7c905a5d643cf785912212f6ce1.
Revert "Revert " (CR) msm_fb: display: reduce turn-on display time.""

This reverts commit 3a59656ad252624f9543a2c2b712a1424f9d1e4d.
Revert "SCHEDULER: Autogroup patch group by current user android UID instead of task ID"

This reverts commit ee88dec1d97d67c3cf019435f126678c5fc76e65.
Fixes for GCC error on panel
These four changes fix some compilation warnings. Cutting down is always nice.