[ARM] 3154/1: SharpSL PM Driver updates

Patch from Richard Purdie

Updates to the SharpSL PM driver including cleanups from both
Pavel Machek and myself and updates after the platform device
changes to make it compile again.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>