KVM: remove kvm_arch_has_vcpu_debugfs()

There is no need for this function as all arches have to implement
kvm_arch_create_vcpu_debugfs() no matter what.  A #define symbol
let us actually simplify the code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/arm/arm.c

@@ -144,11 +144,6 @@ out_fail_alloc:
 	return ret;
 }
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return false;
-}
-
 int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 {
 	return 0;