[NET]: Remove comx driver docs.

The drivers have already been removed 3.5 years ago.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/00-INDEX

@@ -24,8 +24,6 @@ baycom.txt
 	- info on the driver for Baycom style amateur radio modems
 bridge.txt
 	- where to get user space programs for ethernet bridging with Linux.
-comx.txt
-	- info on drivers for COMX line of synchronous serial adapters.
 cops.txt
 	- info on the COPS LocalTalk Linux driver
 cs89x0.txt