KVM: arm/arm64: vgic-new: enable build

Now that the new VGIC implementation has reached feature parity with
the old one, add the new files to the build system and add a Kconfig
option to switch between the two versions.
We set the default to the new version to get maximum test coverage,
in case people experience problems they can switch back to the old
behaviour if needed.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/hyp/vgic-v2-sr.c

@@ -21,7 +21,12 @@
 
 #include <asm/kvm_hyp.h>
 
+#ifdef CONFIG_KVM_NEW_VGIC
+extern struct vgic_global kvm_vgic_global_state;
+#define vgic_v2_params kvm_vgic_global_state
+#else
 extern struct vgic_params vgic_v2_params;
+#endif
 
 static void __hyp_text save_maint_int_state(struct kvm_vcpu *vcpu,
 					    void __iomem *base)