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

This reverts commit 4646af6b0dae064e2d320c7af58e52203cf358d7.
Revert "Revert "fix GPU stuff""

This reverts commit fbe5bdb33ffcaef2d0e7eebbef9df8b2a857ef95.