arm/arm64: KVM: Add hook for C-based stage2 init

As we're about to move the stage2 init to C code, introduce some
C hooks that will later be populated with arch-specific implementations.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/include/asm/kvm_host.h

@@ -220,6 +220,10 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr,
 	kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr);
 }
 
+static inline void __cpu_init_stage2(void)
+{
+}
+
 static inline int kvm_arch_dev_ioctl_check_extension(long ext)
 {
 	return 0;