mfd: Add module.h to the implicit drivers/mfd users

With the pending module.h cleanup, these files will fail to compile,
unless they explicitly call out the include of this file.

[omap-usb-host addition courtesy of Anand Gadiyar <gadiyar@ti.com>]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drivers/mfd/twl-core.c

@@ -30,6 +30,7 @@
 
 #include <linux/init.h>
 #include <linux/mutex.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/err.h>