MAINTAINERS: Update MPTCP maintainer list and CREDITS

My responsibilities at Intel have changed, so I'm handing off exclusive
MPTCP subsystem maintainer duties to Matthieu. It has been a privilege
to see MPTCP through its initial upstreaming and first few years in the
upstream kernel!
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20230120231121.36121-1-mathew.j.martineau@linux.intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

CREDITS

@@ -2489,6 +2489,13 @@ D: XF86_Mach8
 D: XF86_8514
 D: cfdisk (curses based disk partitioning program)
 
+N: Mat Martineau
+E: mat@martineau.name
+D: MPTCP subsystem co-maintainer 2020-2023
+D: Keyctl restricted keyring and Diffie-Hellman UAPI
+D: Bluetooth L2CAP ERTM mode and AMP
+S: USA
+
 N: John S. Marvin
 E: jsm@fc.hp.com
 D: PA-RISC port

MAINTAINERS

@@ -14633,7 +14633,6 @@ F:	net/netfilter/xt_SECMARK.c
 F:	net/netlabel/
 
 NETWORKING [MPTCP]
-M:	Mat Martineau <mathew.j.martineau@linux.intel.com>
 M:	Matthieu Baerts <matthieu.baerts@tessares.net>
 L:	netdev@vger.kernel.org
 L:	mptcp@lists.linux.dev