MAINTAINERS: update s390 file patterns

We were missing some files, and some files should get an additional
entry to add the people actually looking after the code.

Reported-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index fc8abe8..9585a8b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -237,9 +237,12 @@
 M: Alexander Graf <agraf@suse.de>
 S: Maintained
 F: target-s390x/kvm.c
+F: target-s390x/ioinst.[ch]
+F: target-s390x/machine.c
 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
 
 X86
 M: Paolo Bonzini <pbonzini@redhat.com>
@@ -637,14 +640,11 @@
 M: Alexander Graf <agraf@suse.de>
 S: Supported
 F: hw/char/sclp*.[hc]
-F: hw/s390x/s390-virtio-ccw.c
-F: hw/s390x/css.[hc]
-F: hw/s390x/sclp*.[hc]
-F: hw/s390x/ipl*.[hc]
-F: hw/s390x/*pci*.[hc]
-F: hw/s390x/s390-skeys*.c
+F: hw/s390x/
+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
 
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