testing/linux-powkiddy-x55: WiFi improvements

This is another workaround for earlier problem on device, when loading Bluetooth and WiFi modules simultaneously led to non-working WiFi.

Here I'm building and packaging lwfinger/rtw88 driver as replacement of mainline one. It worked even better and more stable during my testing.

Turn's out that for WiFi to be fixed small DTB patch is needed.

Additionally, updated kernel config to pass kconfig check test (except UEFI stuff, which is not available on device).