arm64: dts: allwinner: orange-pi-3: Enable UART1 / Bluetooth

The board contains AP6256 WiFi/BT module that has its bluetooth part
connected to SoC's UART1 port. Enable this port, and add node for the
bluetooth device.

Bluetooth part is named bcm4345c5.

You'll need a BCM4345C5.hcd firmware file that can be found in the
Xulongs's repository for H6:

https://github.com/orangepi-xunlong/OrangePiH6_external/tree/master/ap6256

The driver expects the firmware at the following path relative to the
firmware directory:

  brcm/BCM4345C5.hcd
Signed-off-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>

arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts

@@ -15,6 +15,7 @@ / {
 
 	aliases {
 		serial0 = &uart0;
+		serial1 = &uart1;
 	};
 
 	chosen {
@@ -269,6 +270,24 @@ &uart0 {
 	status = "okay";
 };
 
+/* There's the BT part of the AP6256 connected to that UART */
+&uart1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart1_pins>, <&uart1_rts_cts_pins>;
+	uart-has-rtscts;
+	status = "okay";
+
+	bluetooth {
+		compatible = "brcm,bcm4345c5";
+		clocks = <&rtc 1>;
+		clock-names = "lpo";
+		device-wakeup-gpios = <&r_pio 1 2 GPIO_ACTIVE_HIGH>; /* PM2 */
+		host-wakeup-gpios = <&r_pio 1 1 GPIO_ACTIVE_HIGH>; /* PM1 */
+		shutdown-gpios = <&r_pio 1 4 GPIO_ACTIVE_HIGH>; /* PM4 */
+		max-speed = <1500000>;
+	};
+};
+
 &usb2otg {
 	/*
 	 * This board doesn't have a controllable VBUS even though it