xen: xenbus: quirk uses x86 specific cpuid

This breaks on ARM. This quirk is not necessary on ARM because no
hypervisors of that vintage exist for that architecture (port is too
new).

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[v1: Moved the ifdef inside the function per Jan Beulich suggestion]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index f5dda83..acedeab 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -627,6 +627,7 @@
  */
 static bool xen_strict_xenbus_quirk(void)
 {
+#ifdef CONFIG_X86
 	uint32_t eax, ebx, ecx, edx, base;
 
 	base = xen_cpuid_base();
@@ -634,6 +635,7 @@
 
 	if ((eax >> 16) < 4)
 		return true;
+#endif
 	return false;
 
 }