MAINTAINERS: add Julian Wiedmann

Add Julian Wiedmann as additional maintainer for drivers/s390/net
and net/iucv.
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -10808,6 +10808,7 @@ F:	drivers/s390/block/dasd*
 F:	block/partitions/ibm.c
 
 S390 NETWORK DRIVERS
+M:	Julian Wiedmann <jwi@linux.vnet.ibm.com>
 M:	Ursula Braun <ubraun@linux.vnet.ibm.com>
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
@@ -10838,6 +10839,7 @@ S:	Supported
 F:	drivers/s390/scsi/zfcp_*
 
 S390 IUCV NETWORK LAYER
+M:	Julian Wiedmann <jwi@linux.vnet.ibm.com>
 M:	Ursula Braun <ubraun@linux.vnet.ibm.com>
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/