arm: fix implicit module.h users by adding it to arch/arm as required.

These files will fail to compile if we dont clean them up in advance
and have them include the appropriate headers they need.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/arm/mach-omap1/mailbox.c b/arch/arm/mach-omap1/mailbox.c
index c0e1f48..e962926 100644
--- a/arch/arm/mach-omap1/mailbox.c
+++ b/arch/arm/mach-omap1/mailbox.c
@@ -9,6 +9,7 @@
  * for more details.
  */
 
+#include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>