arm64: KVM: Implement vgic-v2 save/restore

Implement the vgic-v2 save restore (mostly) as a direct translation
of the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 1949fe5..d31e4e5 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -10,6 +10,7 @@
 ARM=../../../arch/arm/kvm
 
 obj-$(CONFIG_KVM_ARM_HOST) += kvm.o
+obj-$(CONFIG_KVM_ARM_HOST) += hyp/
 
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o