xen kconfig: fix select INPUT_XEN_KBDDEV_FRONTEND

A randconfig compile test discovered that we can select
INPUT_XEN_KBDDEV_FRONTEND without all of its dependencies being met. Fix
this by adding the dependency to the select line.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/video/Kconfig

@@ -2277,7 +2277,7 @@ config XEN_FBDEV_FRONTEND
 	select FB_SYS_IMAGEBLIT
 	select FB_SYS_FOPS
 	select FB_DEFERRED_IO
-	select INPUT_XEN_KBDDEV_FRONTEND
+	select INPUT_XEN_KBDDEV_FRONTEND if INPUT_MISC
 	select XEN_XENBUS_FRONTEND
 	default y
 	help