Optimized ARM RWSEM algorithm

RWSEM implementation for ARM using atomic functions.
Heavily based on arch/sh/include/asm/rwsem.h

Signed-off-by: Ashwin Chaugule <ashwinc@codeaurora.org>
fs/kernel: -O3 fixes

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
fail