backlight: s6e63m0: reorder inclusions of <linux/xxx.h>

Reorder inclusions of <linux/xxx.h> for redability, according to
alphabetical ordering.  Also, unnecessary header comments are removed.

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