spi: Add module.h to implicit users in drivers/spi

We are clipping down the presence of module.h, since it was
everywhere.  If you really need it, you better call it out,
as per this changeset.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/spi/spi-au1550.c b/drivers/spi/spi-au1550.c
index bddee5f5..5784c87 100644
--- a/drivers/spi/spi-au1550.c
+++ b/drivers/spi/spi-au1550.c
@@ -25,6 +25,7 @@
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
+#include <linux/module.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/resource.h>