drivers/video/backlight/adp88?0_bl.c: fix resume

commit 5eb02c01bd1f3ef195989ab05e835e2b0711b5a9 upstream.

Clearing the NSTBY bit in the control register also automatically clears
the BLEN bit.  So we need to make sure to set it again during resume,
otherwise the backlight will stay off.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>