udev: support by-path devlink for multipath nvme block devices

udev: support by-path devlink for multipath nvme block devices

If multipath feature is enabled, nvme block devices may belong to the
"nvme-subsystem" subsystem, instead of "nvme" subsystem.
(What a confusing name...)

Then, the syspath is something like the following,
    /sys/devices/virtual/nvme-subsystem/nvme-subsys0/nvme0n1
Hence, we need to find the 'real parent' device, such as
    /sys/devices/pci0000:00/0000:00:1c.4/0000:3c:00.0/nvme/nvme0

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=2031810.
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=2124964.
Replaces #24748.