LinuxKPI: 802.11: initialize txq

In 5a9a0d7803382321b5f9fff1deae5fb08463cf1a we omitted the initialization
of the per-hw txq settings. Fix this.

Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Fixes: 5a9a0d7803382321b5f9fff1deae5fb08463cf1a