clocksource: Add missing include of of.h.

This header uses OF_DELCARE_1 which is defined in linux/of.h.

This fixes getting unhelpful compiler error messages about missing ')' before a string constant.

---
 include/linux/clocksource.h | 1 +
 1 file changed, 1 insertion(+)

index 7784b59..47cc33c 100644
@@ -15,6 +15,7 @@
 #include <linux/cache.h>
 #include <linux/timer.h>
 #include <linux/init.h>
+#include <linux/of.h>
 #include <asm/div64.h>
 #include <asm/io.h>
 

1.9.1

Queued for testing.

thanks
-john