linux-firmware: add carl9170 firmware required by kernel module

Add the carl9170 firmware required by the re-enabled carl9170
kernel modules (Bug #267)

http://wireless.kernel.org/en/users/Drivers/carl9170

Bug #268 http://bugzilla.vyos.net/show_bug.cgi?id=268

Kernel module

Bug #267 http://bugzilla.vyos.net/show_bug.cgi?id=267