KVM: ARM: vgic: split GICv2 backend from the main vgic code

Brutally hack the innocent vgic code, and move the GICv2 specific code
to its own file, using vgic_ops and vgic_params as a way to pass
information between the two blocks.

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 --cc arch/arm/kvm/Makefile
Simple merge

diff --cc arch/arm64/kvm/Makefile
Simple merge

diff --cc include/kvm/arm_vgic.h
Simple merge

diff --cc virt/kvm/arm/vgic-v2.c
Simple merge

diff --cc virt/kvm/arm/vgic.c
Simple merge