arch: add Krait optimisations

https://github.com/CyanogenMod/android_device_asus_flo/commit/b130609be37c74999ce5f77ecdb9668bb50ce729
overlay: set largeHeap for Trebuchet

https://github.com/CyanogenMod/android_device_asus_flo/commit/b130609be37c74999ce5f77ecdb9668bb50ce729
bootanim: preload, use texture cache and rgb565