Don't save and restore cp register 15 since it is only a test register on S3C2410. This is probably a leftover from the PXA sleep.S from which this was derived.

Supersedes patch 4167.
Signed-off-by: Matt Reimer <mreimer@vpop.net>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>