m4: Spring cleaning

Change-Id: If030e8ee7126cdaf12a6cada60fd0089a70d0573
Revert "m4: camera requires VECTORIMPL_SYMBOLS"

This reverts commit 2d96f3a26571f7fdcb51084de30a269f8d1b6f49.

Change-Id: Ic58cc7f53ca24d2e289720c0734faaa3f5676185
m4: Camera doesn't need PMEM heap anymore

Change-Id: Ice708cd8c58b3c22a5e02e4face0ad229ab8568a