MAINTAINERS: Add sctp headers to the general netdev entry

All SCTP patches are picked up by netdev maintainers. Two headers were
missing to be listed there.

Reported-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/b3c2dc3a102eb89bd155abca2503ebd015f50ee0.1739193671.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: marceloleitner

MAINTAINERS

@@ -16508,6 +16508,7 @@ F:	include/linux/netdev*
 F:	include/linux/netlink.h
 F:	include/linux/netpoll.h
 F:	include/linux/rtnetlink.h
+F:	include/linux/sctp.h
 F:	include/linux/seq_file_net.h
 F:	include/linux/skbuff*
 F:	include/net/
@@ -16524,6 +16525,7 @@ F:	include/uapi/linux/netdev*
 F:	include/uapi/linux/netlink.h
 F:	include/uapi/linux/netlink_diag.h
 F:	include/uapi/linux/rtnetlink.h
+F:	include/uapi/linux/sctp.h
 F:	lib/net_utils.c
 F:	lib/random32.c
 F:	net/