ar9170: add support for 1-stage firmware

ar9170: add support for 1-stage firmware

You can get the stage 1 firmware from here:

http://www.kernel.org/pub/linux/kernel/people/mcgrof/firmware/ar9170/ar9170.fw

md5sum: 34feec4ec0eae3bb92c7c1ea2dfb4530
sha1sum: 6e5250498b815c2940d97242de31e054ae44e079

Its license:

http://www.kernel.org/pub/linux/kernel/people/mcgrof/firmware/ar9170/LICENSE

This is a new firmware, tested with WNDA3100.

Cc: Peter Grabienski <Peter.Grabienski@Atheros.com>
Cc: Stephen Chen <Stephen.Chen@Atheros.com>
Cc: Michael Fortin <Michael.Fortin@Atheros.com>
Cc: Johnny Cheng <Johnny.Cheng@Atheros.com>
Cc: Yuan-Gu Wei <Yuan-Gu.Wei@atheros.com>
Cc: Joerg Albert <jal2@gmx.de>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>