dt-bindings: bluetooth: broadcom: Add BCM4349B1 DT binding

The BCM4349B1, aka CYW/BCM89359, is a WiFi+BT chip and its Bluetooth
portion can be controlled over serial.
Extend the binding with its DT compatible.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>