ARM: OMAP: Include missing header

Include missing header for do_div()

Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clock.c

@@ -27,6 +27,7 @@
 
 #include <asm/arch/clock.h>
 #include <asm/arch/sram.h>
+#include <asm/div64.h>
 
 #include "prcm-regs.h"
 #include "memory.h"