MAINTAINERS: update virtio-ccw/s390 git tree

Let's reference the git branch I actually use, and add Christian's
git tree.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

MAINTAINERS

@@ -243,6 +243,8 @@ F: hw/intc/s390_flic.c
 F: hw/intc/s390_flic_kvm.c
 F: include/hw/s390x/s390_flic.h
 F: gdb-xml/s390*.xml
+T: git git://github.com/cohuck/qemu.git s390-next
+T: git git://github.com/borntraeger/qemu.git s390-next
 
 X86
 M: Paolo Bonzini <pbonzini@redhat.com>
@@ -645,7 +647,8 @@ X: hw/s390x/s390-virtio-bus.[ch]
 F: include/hw/s390x/
 F: pc-bios/s390-ccw/
 F: hw/watchdog/wdt_diag288.c
-T: git git://github.com/cohuck/qemu virtio-ccw-upstr
+T: git git://github.com/cohuck/qemu.git s390-next
+T: git git://github.com/borntraeger/qemu.git s390-next
 
 UniCore32 Machines
 -------------
@@ -872,7 +875,8 @@ M: Cornelia Huck <cornelia.huck@de.ibm.com>
 M: Christian Borntraeger <borntraeger@de.ibm.com>
 S: Supported
 F: hw/s390x/virtio-ccw.[hc]
-T: git git://github.com/cohuck/qemu virtio-ccw-upstr
+T: git git://github.com/cohuck/qemu.git s390-next
+T: git git://github.com/borntraeger/qemu.git s390-next
 
 virtio-input
 M: Gerd Hoffmann <kraxel@redhat.com>