[PATCH] SharpSL: Add missing hunk from backlight update

This hunk from the sharpsl/corgi backlight update appears to have got lost
somewhere along the way.  Its needed to match the other changes.

Signed-Off-By: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>