KVM: ARM: Add dummy kvm_arch_init_irq_routing()

The common KVM code insists on calling kvm_arch_init_irq_routing()
as soon as it sees kernel header support for it (regardless of whether
QEMU supports it).  Provide a dummy function to satisfy this.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target-arm/kvm.c

@@ -491,3 +491,7 @@ void kvm_arch_remove_all_hw_breakpoints(void)
 {
     qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
 }
+
+void kvm_arch_init_irq_routing(KVMState *s)
+{
+}