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>

drivers/spi/spi-s3c24xx.c

@@ -24,6 +24,7 @@
 
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
+#include <linux/module.h>
 
 #include <plat/regs-spi.h>
 #include <mach/spi.h>