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

The module.h was implicitly everywhere, but when we clean
that up, the implicit users will compile fail; fix them up
in advance.

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

drivers/rtc/rtc-ds1672.c

@@ -11,6 +11,7 @@
 
 #include <linux/i2c.h>
 #include <linux/rtc.h>
+#include <linux/module.h>
 
 #define DRV_VERSION "0.4"