arm64: KVM: split GICv2 world switch from hyp code

Move the GICv2 world switch code into its own file, and add the
necessary indirection to the arm64 switch code.

Also introduce a new type field to the vgic_params structure.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
index 940418e..d6c9c14 100644
--- a/virt/kvm/arm/vgic-v2.c
+++ b/virt/kvm/arm/vgic-v2.c
@@ -236,6 +236,7 @@
 	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
 		 vctrl_res.start, vgic->maint_irq);
 
+	vgic->type = VGIC_V2;
 	*ops = &vgic_v2_ops;
 	*params = vgic;
 	goto out;