[L2TP]: Add PPPoL2TP maintainer

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -2903,6 +2903,11 @@ P:	Michal Ostrowski
 M:	mostrows@speakeasy.net
 S:	Maintained
 
+PPP OVER L2TP
+P:	James Chapman
+M:	jchapman@katalix.com
+S:	Maintained
+
 PREEMPTIBLE KERNEL
 P:	Robert Love
 M:	rml@tech9.net