Isolate CAIF transport drivers into their own menu

Isolate CAIF transport drivers into their own menu.

This cleans up the main Network device support menu,
makes it easier to find the CAIF drivers, and makes it
easier to enable/disable them as a group.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/caif/Kconfig

@@ -3,7 +3,13 @@
 # CAIF physical drivers
 #
 
-comment "CAIF transport drivers"
+menuconfig CAIF_DRIVERS
+	bool "CAIF transport drivers"
+	depends on CAIF
+	help
+	  Enable this to see CAIF physical drivers.
+
+if CAIF_DRIVERS
 
 config CAIF_TTY
 	tristate "CAIF TTY transport driver"
@@ -55,3 +61,5 @@ config CAIF_VIRTIO
 if CAIF_VIRTIO
 source "drivers/vhost/Kconfig.vringh"
 endif
+
+endif # CAIF_DRIVERS