udev-builtin-net_id: Add DeviceTree-based names for WLAN devices
Add support for generating names like wldN based on DeviceTree aliases.
DeviceTree alias names follow de facto conventions. As of writing, there
are so far two ways WLAN devices are represented in DeviceTree aliases
in upstream Linux DTS files:
- Firstly, as wifi0, used for example in t600x-j314-j316.dtsi
- Secondly, as ethernet0 or ethernet1, used for example in
sun8i-q8-common.dtsi, with a comment saying the reason is to "Make
u-boot set mac-address for wifi without an eeprom"
Therefore for prefix "wl", try alias_prefix "wifi" first, and if that
was not found, fall back to alias_prefix "ethernet"
Since this is a naming scheme change, also gate this behind
NAMING_DEVICETREE_ALIASES_WLAN and NAMING_V259, and document this
change.