linux-xiaomi-tissot: upgrade to 4.9.188

I ported Xiaomi Mi A1 (tissot) to the latest LineageOS kernel (4.9.188). With those changes following features work (same as on old kernel):

• USB Networking
• Flashing
• Touchscreen
• Display
• WiFi

xiaomi-tissot:~$ uname -a
Linux xiaomi-tissot 4.9.188-perf #1-postmarketOS SMP PREEMPT Thu Aug 6 18:48:54 UTC 2020 aarch64 Linux