arm64: KVM: Add VGIC device control for arm64

This fixes the build breakage introduced by
c07a0191ef2de1f9510f12d1f88e3b0b5cd8d66f and adds support for the device
control API and save/restore of the VGIC state for ARMv8.

The defines were simply missing from the arm64 header files and
uaccess.h must be implicitly imported from somewhere else on arm.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index be456ce..8ca405c 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/uaccess.h>
 
 #include <linux/irqchip/arm-gic.h>