udev: Fix by-uuid symlink for ubifs volumes

udev: Fix by-uuid symlink for ubifs volumes

ubifs volumes have a UUID and the built-in blkid is able to determine
it.  The disk/by-uuid symlink isn't created because ubifs volumes are
not on block devices but on SUBSYSTEM="ubi" devices.  See #20071.

Allow ubi subsystem devices to be processed by the persistent storage
rules too.  The kernel device name matching already allows ubi* to pass.
The existing rules are sufficient to create the link.

The links look like other by-uuid symlinks, for example:
/dev/disk/by-uuid/9a136158-585b-4ba4-9b70-cbaf2cf78a1c -> ../../ubi0_1