firewire: add includes for sem and rw_sem

as a precaution.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 15721a7..415e9ab 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -26,6 +26,8 @@
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/idr.h>
+#include <linux/rwsem.h>
+#include <asm/semaphore.h>
 #include "fw-transaction.h"
 #include "fw-topology.h"
 #include "fw-device.h"