network.subr: adjust regex for wlans_xxxxx rc.conf entries

[bz]

Summary

Drivers like ath10k and ath11k will not match the current regex as
they have digits followed by letters. Adjust the regex to allow
this combination in order to be able to configure interfaces with
names like wlans_ath11k0="..."

MFC after: 7 days

[bz]

Anyone?

[emaste]

Or maybe [a-z]+[a-z0-9]+[0-9]+?

[bz]

In D39674#903852, @emaste wrote:

Or maybe [a-z]+[a-z0-9]+[0-9]+?

Probably very wise, I'll update in a second.

[bz]

Ehance the regex further as suggested by @emaste