AArch64: Add qemu capabilities schemeta for test.

Add qemu AArch64 capabilities schemeta in caps-qemu-kvm.xml.
Signed-off-by: NAnup Patel <anup.patel@linaro.org>
Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org>

(crobinso: add aarch64 to schema arch list)

docs/schemas/basictypes.rng

@@ -298,6 +298,7 @@
 
   <define name='archnames'>
     <choice>
+      <value>aarch64</value>
       <value>alpha</value>
       <value>armv7l</value>
       <value>cris</value>

tests/capabilityschemadata/caps-qemu-kvm.xml

@@ -111,6 +111,17 @@
     </arch>
   </guest>
 
+  <guest>
+    <os_type>hvm</os_type>
+    <arch name='aarch64'>
+      <wordsize>64</wordsize>
+      <emulator>/usr/bin/qemu-system-aarch64</emulator>
+      <machine>machvirt</machine>
+      <domain type='qemu'>
+      </domain>
+    </arch>
+  </guest>
+
   <guest>
     <os_type>hvm</os_type>
     <arch name='microblaze'>