Add the missing header include for spinlocks, to avoid potential build
failures on specific architectures or configurations.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>