Makefile: clean up optimization flags

Signed-off-by: Sultanxda <sultanxda@gmail.com>
Revert "Added misc optimizations"

This reverts commit 9dcbfd495329c2b7786ef1818917456a0e18a863.
Revert "Updated LMK and random.c to Linux next, added misc optimizations"

This reverts commit 3d4b2ff50dc1353895c75ea14be17511bc3a7392.

Conflicts:
	drivers/staging/android/lowmemorykiller.c
Update optimization flags