Convert USB hostdevices over to -device

The old syntax was

   -usbdevice host:PRODUCT:VENDOR

Or

   -usbdevice host:BUS.DEV

The new syntax is

   -device usb-host,product=PRODUCT,vendor=VENDOR

Or

   -device usb-host,hostbus=BUS,hostaddr=DEV

tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.xml

@@ -0,0 +1,27 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219200</memory>
+  <currentMemory>219200</currentMemory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>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</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+    </disk>
+    <hostdev mode='subsystem' type='usb' managed='no'>
+      <source>
+        <address bus='14' device='6'/>
+      </source>
+    </hostdev>
+  </devices>
+</domain>