staging: add ath6kl driver for AR6003 chip

staging: add ath6kl driver for AR6003 chip

AR6003 is a single stream, SDIO based 802.11 chipset from
Atheros optimized for mobile and embedded devices. ath6kl is a
cfg80211 driver for AR6003 and supports both the station and
AP mode of operation.

Station mode supports 802.11 a/b/g/n with HT20 on 2.4/5GHz and
HT40 only on 5GHz. Some of the other features include WPA/WPA2,
WPS, WMM, WMM-PS, and BT coexistence. AP mode can be operated
only in b/g mode with support for a subset of features mentioned
above.

The driver supports cfg80211 but comes with its own set of
wext ioctls which have historically supported some of our
customers with features like BT 3.0 and AP mode of operation.

For further details, please refer to:

http://wireless.kernel.org/en/users/Drivers/ath6kl

The driver requires firmware that runs on the chip's network
processor. The majority of it is stored in ROM. The binaries
that are downloaded and executed from RAM are as follows:

1) Patch against the code in ROM for bug fixes and feature
   enhancements.
2) Code to copy the data from the OTP region of the memory
   into RAM.
3) Calibration file carrying board specific data.

The above files need to be present in the directory
'/lib/firmware/ath6k/AR6003/hw2.0/' for the driver to initialize
the chip upon enumeration. The files can be downloaded from the
link specified at the following location:

http://wireless.kernel.org/en/users/Drivers/ath6kl#Download

This driver is only provided in the interim while we work on
the mac80211 replacement, ath6k. Once the mac80211 driver
achieves feature parity with the ath6kl driver, the ath6kl will
be deprecated and removed from staging.

Signed-off-by: Vipin Mehta <vmehta@atheros.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>