Update EXFAT Driver to 1.2.8 from my source.

Conflicts:
	fs/exfat/Makefile
	fs/exfat/exfat_super.c
	fs/exfat/exfat_version.h
enable aio in defconfig
Revert "aio.c updated to experimental/android-3.14"

This reverts commit 601e92d28d57c9e40845746565e25f2c7f139787.