R1350 YA105 board-data A/B test

Evidence:
- QCA9888 runtime board ID is bmi-chip-id=0,bmi-board-id=24 (0x18).
- Xiaomi/QSDK maps QCA9888 board ID 0x18 to YA105.
- Xiaomi boarddata_0.bin is byte-identical to YA105.
- Generic OpenWrt board-2.bin entry 0:24 was NOT byte-identical to Xiaomi YA105.

This image uses upstream ath10k and keeps the unit-specific ART pre-calibration,
but replaces only board-2.bin entry 0:24 with Xiaomi/QSDK YA105.
It does not embed the unit ART/MAC/calibration dump.

TEST ONLY. Prefer initramfs RAM boot. Keep serial/programmer recovery available.
Use identical CN/channel 149/VHT80/client position and compare RSSI/retries.
Collect:
 dmesg | grep -iE 'ath10k|board|cal|firmware'
 iw dev phy0-ap0 info
 iw dev phy0-ap0 station dump
