ARM: versatile: ensure sched_clock() is notrace

Include sched.h to ensure sched_clock() has the notrace
annotation.
Signed-off-by: Rabin Vincent <rabin@rab.in>

arch/arm/plat-versatile/sched-clock.c

@@ -20,6 +20,7 @@
  */
 #include <linux/cnt32_to_63.h>
 #include <linux/io.h>
+#include <linux/sched.h>
 #include <asm/div64.h>
 
 #include <mach/hardware.h>