hvc_xen: introduce HVC_XEN_FRONTEND

Introduce a new config option HVC_XEN_FRONTEND to enable/disable the
xenbus based pv console frontend.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 4222035..192e21e 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig
@@ -76,6 +76,14 @@
 	help
 	  Xen virtual console device driver
 
+config HVC_XEN_FRONTEND
+	bool "Xen Hypervisor Multiple Consoles support"
+	depends on HVC_XEN
+	select XEN_XENBUS_FRONTEND
+	default y
+	help
+	  Xen driver for secondary virtual consoles
+
 config HVC_UDBG
        bool "udbg based fake hypervisor console"
        depends on PPC && EXPERIMENTAL