[S390] cio: introduce notifier for boxed state

If a ccw device did not respond in time during internal io, we set it
into boxed state. With this patch we have the following behaviour:
 * the ccw driver will get a notification if the device was online and
   goes into the boxed state
 * if the device was disconnected and got boxed nothing special is to be
   done (it will be handled in reprobing later)
 * if the device got boxed while initial sensing it will be unregistered

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 2fd64e5..0570794 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2363,6 +2363,7 @@
 	ret = 0;
 	switch (event) {
 	case CIO_GONE:
+	case CIO_BOXED:
 	case CIO_NO_PATH:
 		/* First of all call extended error reporting. */
 		dasd_eer_write(device, NULL, DASD_EER_NOPATH);