mako: Add overlay for gamma control semantics

This change will allow for gamma control heading strings to be
set on a per-device basis, mako in this instance.

Change-Id: I51507e104a9f32a2f18359fa8151e0185d1644bc
Merge "mako: Add overlay for gamma control semantics" into cm-10.2
merge changes from CyanogenMod 10.2 into local branch
mako: Use CAF media driver

 * Build codecs, update configs
 * Improves WFD performance

Change-Id: I54c310ca8bb6e687a41cda72a17a722f4fe6b264

Conflicts:
	device.mk