libc: krait: Implement optimized versions of memmove and bcopy

Code has been refactored to thumb2 for consistency with the rest
of bionic libc, as well as performance and correctness.

Use memove & bcopy in cortex-a53.

Change-Id: I5f738ef3eb12ece6b55285f1588eab3d4bbbe27d
4 files changed