linux-firmware: ath6k: add AR6003 hw2.1.1 firmware version 3.2.0.144

As there are ABI changes increase the API version to 3 and firmware file
is named fw-3.bin.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

WHENCE

@@ -1790,6 +1790,7 @@ File: ath6k/AR6003/hw1.0/bdata.WB31.bin
 File: ath6k/AR6003/hw1.0/athwlan.bin.z77
 File: ath6k/AR6003/hw2.1.1
 File: ath6k/AR6003/hw2.1.1/fw-2.bin
+File: ath6k/AR6003/hw2.1.1/fw-3.bin
 File: ath6k/AR6003/hw2.1.1/otp.bin
 File: ath6k/AR6003/hw2.1.1/athwlan.bin
 File: ath6k/AR6003/hw2.1.1/endpointping.bin