Revert "Revert "Revert "ARM: rwsem: use asm-generic rwsem implementation"""

This reverts commit f0a04996fdd5e3860a7c1dbf0c7df582a44ad85f.
Revert "Revert "Revert "Revert "ARM: rwsem: use asm-generic rwsem implementation""""

This reverts commit 2725926c4b807bddddf22fea8eaefb91cd57c3ff.