Make our PV drivers "Novell supported modules"

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>

Index: xen-4.0.0-testing/unmodified_drivers/linux-2.6/Module.supported
===================================================================
--- /dev/null
+++ xen-4.0.0-testing/unmodified_drivers/linux-2.6/Module.supported
@@ -0,0 +1,5 @@
+xen-vbd
+xen-platform-pci
+xen-vnif
+xenbus
+xen-balloon