Fix toogle whether xenbus driver should be built as module or part of kernel.

The "select" statement in the Kconfig ensures that all other users
of the xenbus will have the same dependency.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 3b54b39..1b332d1 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2070,6 +2070,7 @@
 	select FB_SYS_IMAGEBLIT
 	select FB_SYS_FOPS
 	select FB_DEFERRED_IO
+	select XEN_XENBUS_FRONTEND
 	default y
 	help
 	  This driver implements the front-end of the Xen virtual