Add optimized version of memset for Cortex A9

Adds new code to function memset, optimized for Cortex A9.

Copyright (C) ST-Ericsson SA 2010

Added neon implementation

Author: Henrik Smiding henrik.smiding@stericsson.com for ST-Ericsson.

Change-Id: Id3c87767953439269040e15bd30a27aba709aef6
Signed-off-by: Christian Bejram <christian.bejram@stericsson.com>

Conflicts:

	libc/arch-arm/bionic/memset.S