Use a generic procd service around the foreground BlueZ btattach utility.
Configure the UART, protocol and speed through UCI, without router
identity checks or GPIO operations in the attachment service.
Leave attachment disabled and the device unset by default. Keep board
wiring in the device tree and use the existing HCI UART and BlueZ packages.
Tested controller startup after cold power-on, LE discovery, connection
and service discovery on LN6001.
Signed-off-by: Satoshi Ikeuchi <satosan.ikm@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/25594
Signed-off-by: Robert Marko <robimarko@gmail.com>
