ath79: ZTE MF281: use specific board definition file for qca9888

Using board definition file extracted from stock firmware yields 50%
throughput improvement in RX direction under iperf3 test.
Make the device use temporary files from firmware_qca-wireless.git
temporarily, as well as select the specific variant in the device tree
files. The device uses same board file as the MF286C.

Signed-off-by: Lech Perczak <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/17620
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/ath79/dts/qca9563_zte_mf281.dts

@@ -158,6 +158,8 @@
 &wifi_ath10k {
 	nvmem-cells = <&macaddr_mac_0 1>, <&cal_caldata_5000>;
 	nvmem-cell-names = "mac-address", "pre-calibration";
+	/* Board file from stock firmware is shared with MF286C */
+	qcom,ath10k-calibration-variant = "ZTE-MF286C";
 };
 
 &pinmux {

target/linux/ath79/image/nand.mk

@@ -458,6 +458,7 @@ define Device/zte_mf281
   IMAGE/factory.bin := append-kernel | pad-to $$$$(KERNEL_SIZE) | append-ubi | \
 	check-size
   DEVICE_PACKAGES += ath10k-firmware-qca9888-ct kmod-usb-net-rndis \
+	-ath10k-board-qca9888 ipq-wifi-zte_mf286c \
 	kmod-usb-acm comgt-ncm
 endef
 TARGET_DEVICES += zte_mf281