Add cmpxchg_local to frv

Use the new generic cmpxchg_local (disables interrupt) for 8, 16 and 64 bits
arguments. Use the 32 bits cmpxchg available on the architecture for 32 bits
arguments.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>