libpixelflinger: Include NEON optimized assembly

TARGET_ARCH_VERSION is no longer used, instead we use ARCH_ARM_HAVE_NEON.
Also, include <machine/cpu-features.h> to get ARM optimized routines compiled.

See https://android-review.googlesource.com/#/c/22208/

Change-Id: I6629ec06607a665b9bc5ea4291d159214f57caa7
libpixelflinger: Add ARM NEON optimized scanline_t32cb16

This can dramatically improve the performance of boot animation.

See https://android-review.googlesource.com/#/c/16358/

Change-Id: I9a5aaa09b91d7a5ed892f6518a53e8fa4af88ee5
fix conflict