qemu: vfio-ccw device address generation

Introduces the vfio-ccw model for mediated devices and prime vfio-ccw
devices such that CCW address will be generated.

Alters the qemuxml2xmltest for testing a basic mdev device using vfio-ccw.

Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>

tests/qemuxml2xmloutdata/hostdev-subsys-mdev-vfio-ccw.xml

@@ -0,0 +1,28 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>524288</memory>
+  <currentMemory unit='KiB'>524288</currentMemory>
+  <vcpu placement='static'>2</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-s390x</emulator>
+    <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-ccw'>
+      <source>
+        <address uuid='90c6c135-ad44-41d0-b1b7-bae47de48627'/>
+      </source>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
+    </hostdev>
+    <memballoon model='virtio'>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0001'/>
+    </memballoon>
+    <panic model='s390'/>
+  </devices>
+</domain>