bpf, doc: Update maintainers for L7 BPF

Add Jakub and myself as maintainers for sockmap related code.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200309111243.6982-13-lmb@cloudflare.com

MAINTAINERS

@@ -9363,6 +9363,8 @@ F:	include/net/l3mdev.h
 L7 BPF FRAMEWORK
 M:	John Fastabend <john.fastabend@gmail.com>
 M:	Daniel Borkmann <daniel@iogearbox.net>
+M:	Jakub Sitnicki <jakub@cloudflare.com>
+M:	Lorenz Bauer <lmb@cloudflare.com>
 L:	netdev@vger.kernel.org
 L:	bpf@vger.kernel.org
 S:	Maintained