rename_device: also support dracut-style kernel cmdline configuration

[lnykryn]

There are 2 cases where this might be useful.

• On machines with initrd build without dracut-network, you can now still use ifname option
• On older kernels where double renaming was allowed, normal system replaced the name set by initrd.

[lnykryn]

@jamacku @msekletar What do you think? https://bugzilla.redhat.com/show_bug.cgi?id=1851503

[jamacku]

@dtardon Thank you for review.

Rename-devices will be reworked in rust, so I'll merge this one, so we won't forgot about this feature.