drivers/video/backlight/Makefile: cleanup

Fix up indenting.  Also alphasort all entries, which reduces patch
collisions.

Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>