Camera: Support obtaining camera memory from MemoryHeapIon

* Exynos 5 devices want the ION file descriptor from MemoryHeapIon

Change-Id: I9e445cf24c15713f713181667e7b7caa1a96592e
Merge commit 'refs/changes/52/80352/1' of http://review.cyanogenmod.org/CyanogenMod/android_frameworks_av into cm-12.0