s390/rwlock: use the interlocked-access facility 1 instructions

Make use of the load-and-add, load-and-or and load-and-and instructions
to atomically update the read-write lock without a compare-and-swap loop.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/asm/spinlock.h
Simple merge

diff --cc arch/s390/lib/spinlock.c
Simple merge