MAINTAINERS: additional files related kvm s390 pci passthrough

Add entries from the s390 kvm subdirectory related to pci passthrough.
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20220606203325.110625-22-mjrosato@linux.ibm.comSigned-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

MAINTAINERS

@@ -17454,6 +17454,7 @@ M:	Eric Farman <farman@linux.ibm.com>
 L:	linux-s390@vger.kernel.org
 L:	kvm@vger.kernel.org
 S:	Supported
+F:	arch/s390/kvm/pci*
 F:	drivers/vfio/pci/vfio_pci_zdev.c
 F:	include/uapi/linux/vfio_zdev.h