Bluetooth: btmtkuart: add an implementation for clock osc property

Some board requires explicitily control external osscilator via GPIO.
So, add an implementation of a clock property for an external oscillator
to the device.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
1 file changed