ath: fix SPDX tags

Commit ec8f24b7faaf ("treewide: Add SPDX license identifier -
Makefile/Kconfig") marked various Makefiles and Kconfig files within ath
directories as GPL-2.0. But these modules and drivers are actually ISC:

* ath
* ar5523
* ath10k
* ath5k
* ath6kl
* ath9k
* wcn36xx
* wil6210

Fix SPDX tags accordingly.

Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ar5523: Add new driver

This driver is for the AR5523 chipset from Atheros. It was created
in 2007 by Christoph Hellwig but it was never finished. I found it a
couple of months ago and after some polishing it's working pretty
fine.

The driver was written with the FreeBSD driver (uath) as reference,
which was written with the reverse-engineered windows driver as
reference, hence the feature set is very limited. Station mode
only, no HW crypto offload.

Signed-off-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>