Revert "Revert "ARM: 7173/1: Add optimised swahb32() byteswap helper for v6 and above""

This reverts commit 5494b160bf41b721aaaf6f15a2ce9b8dc0fcdabc.
Revert "Revert "ARM: spinlock: use ticket algorithm for ARMv6+ locking implementation""

This reverts commit 2ae3e22a99c7e6dfaa986cc2df45696a0937272e.