can-j1939: remove obsolete sections from documentation

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can-j1939.md

@@ -63,26 +63,6 @@ will emit a single CAN frame.
 
 will use fragementation, emitting 1+ CAN frames.
 
-## Enable j1939 (obsolete!)
-
-CAN has no protocol id field.
-The can-j1939 stack only activates when a socket opens
-for a network device.
-
-The methods described here existed in earlier implementations.
-
-### netlink
-
-	ip link set can0 j1939 on
-
-This method is obsoleted in favor of _on socket connect_.
-
-### procfs for legacy kernel (2.6.25)
-
-This API is dropped for kernels with netlink support!
-
-	echo can0 > /proc/net/can-j1939/net
-
 # Using J1939
 
 ## BSD socket implementation
@@ -116,16 +96,3 @@ This API is dropped for kernels with netlink support!
 
   * When providing address information,
     *name* != 0 indicates dynamic addressing
-
-## iproute2 (obsolete!)
-
-Older versions of can-j1939 used a modified iproute2
-for manipulating the kernel lists of current addresses.
-
-### Static addressing
-
-	ip addr add j1939 0x80 dev can0
-
-### Dynamic addressing
-
-	ip addr add j1939 name 0x012345678abcdef dev can0