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>
diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c
index ddbc797..6186833 100644
--- a/drivers/rtc/rtc-isl12022.c
+++ b/drivers/rtc/rtc-isl12022.c
@@ -15,6 +15,7 @@
 #include <linux/bcd.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
+#include <linux/module.h>
 
 #define DRV_VERSION "0.1"