net: assign maintainer for include/net.h

include/net.h currently has no maintainer.

Assign include/net.h to the maintainer of the NET subsystem.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index bc67c49..2fcc60f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -616,6 +616,7 @@
 S:	Maintained
 T:	git https://gitlab.denx.de/u-boot/custodians/u-boot-net.git
 F:	drivers/net/
+F:	include/net.h
 F:	net/
 
 NIOS