Support for USB Atheros wireless adapters

[ityshchenko]

Enable ath9_htc module in kernel configuration.

[zhovner]

This module is already enabled. You can see CONFIG_ATH9K_HTC=m in kernel .config.

You probably means a firmware for specific cards? Currently only intel and broadcom firmware enabled. I'm not include all possible firmware because it's too large. I think we need to collect most popular ones.