KVM: PPC: booke: Fix get_tb() compile error on 64-bit

Include header file for get_tb() declaration.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/booke.c

@@ -36,6 +36,7 @@
 #include <asm/dbell.h>
 #include <asm/hw_irq.h>
 #include <asm/irq.h>
+#include <asm/time.h>
 
 #include "timing.h"
 #include "booke.h"