Set default properties for Power: virtual console and scsi driver

This patch enables the virtual console for Power systems /dev/hvc0
and sets scsi bus and virtio-scsi model as default.
The virtual console hvc0 enables full console including dmesg.
High performance virtio-scsi driver keeps the efficient design of
virtio-blk with effective SCSI passthrough.

Change-Id: I0b5cd4a15d30f06fc7993555d91d6907bd1acbd7

Author: Rafael Folco

functions

@@ -301,8 +301,8 @@ function upload_image {
         *) echo "Do not know what to do with $image_fname"; false;;
     esac
 
-    if is_arch "ppc64"; then
-        img_property="--property hw_cdrom_bus=scsi"
+    if is_arch "ppc64le" || is_arch "ppc64" || is_arch "ppc"; then
+        img_property="--property hw_disk_bus=scsi --property hw_scsi_model=virtio-scsi --property hw_cdrom_bus=scsi --property os_command_line=console=hvc0"
     fi
 
     if is_arch "aarch64"; then