Revert "m4: add TARGET_DISPLAY_INSECURE_MM_HEAP"

This reverts commit 262b41bb3fb667a69ef182d57bd15a85e35f0bfc.

Change-Id: I9797db883c48a90e5b269c0ca00d688727d98c50
Merge remote-tracking branch 'cm/cm-12.0' into HEAD