Switch the set/clear/change bitops to use the word-based exclusive
operations, which are only present in a wider range of ARM architectures
than the byte-based exclusive operations.

Tested record:
- Nicolas Pitre: ext3,rw,le
- Sourav Poddar: nfs,le
- Will Deacon: ext3,rw,le
- Tony Lindgren: ext3+nfs,le
Reviewed-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: NSourav Poddar <sourav.poddar@ti.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>