libc: Enable the fast memmove for NEON targets

 * The CodeAurora version of memmove provides roughly 20x the throughput
   of the default version for all tested platforms. Enable it.

Change-Id: Ia9740f6b38a72c0bd6a6818c96d73e2c23bb5979
libc: Remove Scorpion memmove() routine

 * This code is slower than the new implementation under every
   circumstance on Scorpion devices. Remove it and standardize on one
   implementation.
 * Also remove "optimized" memmove_words, which was just a pointer to
   memmove. The performance was identical to the C version on Krait, and
   has regressions on other platforms. This function is only used for
   System.arraycopy in Dalvik.

Change-Id: I42d06fbd7c56d9874b80a0e768dbadf0fa5025a4

Conflicts:
	libc/Android.mk

Signed-off-by: Paul Beeler <sparksco@gmail.com>