KVM: selftests: fix supported_flags for aarch64

KVM/Arm supports readonly memslots; fix the calculation of
supported_flags in set_memory_region_test.c, otherwise the
test fails.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/set_memory_region_test.c

@@ -333,9 +333,11 @@ static void test_invalid_memory_region_flags(void)
 	struct kvm_vm *vm;
 	int r, i;
 
-#ifdef __x86_64__
+#if defined __aarch64__ || defined __x86_64__
 	supported_flags |= KVM_MEM_READONLY;
+#endif
 
+#ifdef __x86_64__
 	if (kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM))
 		vm = vm_create_barebones_protected_vm();
 	else