linux-firmware: update Atheros firmware license

This makes the license Operating System agnostic and updates
the patent license grant for use of the firmware license specifically
on the Atheros chipsets.

This allows us to share the same license between all Atheros chipsets,
ath9k, ath9k_htc, ath6kl, and future chipsets.

Cc: ath9k-devel@atheros.com
Cc: Len Widra <len.widra@atheros.com>
Cc: Brian Lee <briank.lee@atheros.com>
Cc: Adam Tachner <atachner@atheros.com>
Cc: Paul Lever <Paul.Lever@atheros.com>
Cc: Vipin Mehta <vipin.mehta@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

LICENCE.atheros_firmware

@@ -21,9 +21,7 @@ world-wide, royalty-free, non-exclusive license under patents it
 now or hereafter owns or controls to make, have made, use, import,
 offer to sell and sell ("Utilize") this software, but solely to
 the extent that any such patent is necessary to Utilize the software
-alone, or in combination with an operating system licensed under an
-approved Open Source license as listed by the Open Source Initiative
-at http://opensource.org/licenses.  The patent license shall not
+in conjunction with an Atheros Chipset. The patent license shall not
 apply to any other combinations which include this software. No
 hardware per se is licensed hereunder.