MAINTAINERS: Add explicit section for IPSEC networking.

Signed-off-by: David S. Miller <[e-mail]>

MAINTAINERS

···
 F:	include/net/ip*
 F:	arch/x86/net/*
 
+NETWORKING [IPSEC]
+M:	Steffen Klassert <[e-mail]>
+M:	Herbert Xu <[e-mail]>
+M:	"David S. Miller" <[e-mail]>
+L:	[e-mail]
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
+S:	Maintained
+F:	net/xfrm/
+F:	net/key/
+F:	net/ipv4/xfrm*
+F:	net/ipv6/xfrm*
+F:	include/uapi/linux/xfrm.h
+F:	include/net/xfrm.h
+
 NETWORKING [LABELED] (NetLabel, CIPSO, Labeled IPsec, SECMARK)
 M:	Paul Moore <[e-mail]>
 L:	[e-mail]