linux-firmware: Add missing firmware for the carl9170 driver

For a long time now Atheros USB AR9170 devices have been using the
carl9170 driver which relies on the carl9170-1.fw firmware file.  This
firmware is available in linux-firmware but it wasn't currently
installed by Buildroot.

Signed-off-by: Karoly Pados <kp@tec4data.at>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/linux-firmware/linux-firmware.mk

@@ -104,7 +104,7 @@ endif
 
 # ar9170
 ifeq ($(BR2_PACKAGE_LINUX_FIRMWARE_ATHEROS_9170),y)
-LINUX_FIRMWARE_FILES += ar9170-1.fw ar9170-2.fw
+LINUX_FIRMWARE_FILES += ar9170-1.fw ar9170-2.fw carl9170-1.fw
 LINUX_FIRMWARE_ALL_LICENSE_FILES += LICENCE.atheros_firmware
 endif