rules: watch metadata changes in mmcblk devices (systemd#6050)

Formatting sd-cards does not trigger "change" uevents. As a result clients
using udev API don't get any updates afterwards and get outdated information
about the device.

Include mmcblk* in a match for watch option assignment.

Author: kjackiewicz

rules/60-block.rules

@@ -8,4 +8,4 @@ ACTION=="add", SUBSYSTEM=="module", KERNEL=="block", ATTR{parameters/events_dfl_
 ACTION=="change", SUBSYSTEM=="scsi", ENV{DEVTYPE}=="scsi_device", TEST=="block", ATTR{block/*/uevent}="change"
 
 # watch metadata changes, caused by tools closing the device node which was opened for writing
-ACTION!="remove", SUBSYSTEM=="block", KERNEL=="loop*|nvme*|sd*|vd*|xvd*|pmem*", OPTIONS+="watch"
+ACTION!="remove", SUBSYSTEM=="block", KERNEL=="loop*|nvme*|sd*|vd*|xvd*|pmem*|mmcblk*", OPTIONS+="watch"