arm64/xen: use XEN_IO_PROTO_ABI_ARM on ARM64

Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NIan Campbell <ian.campbell@citrix.com>

include/xen/interface/io/protocols.h

@@ -15,7 +15,7 @@
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64
 #elif defined(__powerpc64__)
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_POWERPC64
-#elif defined(__arm__)
+#elif defined(__arm__) || defined(__aarch64__)
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM
 #else
 # error arch fixup needed here