Revert "asm-generic: rwsem: de-PPCify rwsem.h"

This reverts commit ddc16aa7af01e08a24418f0e47ac3a3769af84b6.
Revert "ARM: rwsem: use asm-generic rwsem implementation"

This reverts commit 2e69a936ccde35feee8110e22426170d22c4c348.
Revert "asm-generic: rwsem: ensure sem->cnt is only accessed via atomic_long_*"

This reverts commit a16bd84dc74204f536a146bb033683edb4ae12d0.