xen pvfb: Module aliases to support module autoloading

These are mostly for completeness and consistency with the other
frontends, as PVFB is typically compiled in rather than a module.

Derived from
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/5e294e29a43e

While there, add module descriptions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/input/xen-kbdfront.c b/drivers/input/xen-kbdfront.c
index 9da4452..eaf69cf 100644
--- a/drivers/input/xen-kbdfront.c
+++ b/drivers/input/xen-kbdfront.c
@@ -343,4 +343,6 @@
 module_init(xenkbd_init);
 module_exit(xenkbd_cleanup);
 
+MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("xen:vkbd");