SDM845 devices running mainline lack a valid MAC address, and
fallback to a random one on each boot. This makes DHCP IPs vary
on each boot and breaks Bluetooth BNEP mode since the kernel enforces
that a valid MAC address is used when Bluetooth BNEP mode is activated.
Add a udev rule to trigger a script when the WLAN or Bluetooth interface
appear to set the MAC address by reading it from the persist partition
for the WLAN MAC address and increment it for generating a Bluetooth MAC
address. This approach seems to be common on some downstream devices
such as the Oneplus 6.
[ci:skip-build]: already built successfully in CI
3942f8b1b6