libcopybit: Add missing return statement

Change-Id: I662699b7418eba2c4792ed6c7c7b628762ebe03b
(cherry picked from commit f2e940109252c63b6e21f929e45ba794dfe12b95)
copybit: Fix type conversion error for GCC 4.7

    GCC 4.7 has stricter type conversion rules in copybit.cpp

Change-Id: I7f8572e2d9416ccb2ba17e707c7f75a2e69d69cf
overlay: Allocate from MM heap as a fallback

 * Not all devices support IOMMU yet, so use the MM heap as a fallback.
 * Enabled when NO_IOMMU is set

Change-Id: I9d9f3dffb92f5b4bf45422df0f66a40611943202
display: Cover NO_IOMMU for msm7x30 too

Change-Id: Ic68672f386a06fd0ac9fd1f18eec3188415a8642