MAINTAINERS: add Andrew Lunn as a co-maintainer of all networking drivers

Andrew has been a pillar of the community for as long as I remember.
Focusing on embedded networking, co-maintaining Ethernet PHYs and
DSA code, but also actively reviewing MAC and integrated NIC drivers.
Elevate Andrew to the status of co-maintainer of all netdev drivers.
Acked-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20241011193303.2461769-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -16092,6 +16092,7 @@ F:	include/uapi/linux/net_dropmon.h
 F:	net/core/drop_monitor.c
 
 NETWORKING DRIVERS
+M:	Andrew Lunn <andrew+netdev@lunn.ch>
 M:	"David S. Miller" <davem@davemloft.net>
 M:	Eric Dumazet <edumazet@google.com>
 M:	Jakub Kicinski <kuba@kernel.org>