ARM: dts: bcm2835-rpi-zero-w: Add bcm43438 serial slave

Add BCM43438 (bluetooth) as a serdev slave device of uart0 (pl011/ttyAMA0).
This allows to automatically insert the bcm43438 to the bluetooth
subsystem instead of relying on patched userspace helpers (hciattach).

In order to keep a debug UART we need to switch to uart1.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

arch/arm/boot/dts/bcm2835-rpi-zero-w.dts

@@ -131,6 +131,18 @@ brcmf: wifi@1 {
 
 &uart0 {
 	pinctrl-names = "default";
-	pinctrl-0 = <&uart0_gpio14>;
+	pinctrl-0 = <&uart0_gpio32 &uart0_ctsrts_gpio30>;
+	status = "okay";
+
+	bluetooth {
+		compatible = "brcm,bcm43438-bt";
+		max-speed = <2000000>;
+		shutdown-gpios = <&gpio 45 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&uart1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart1_gpio14>;
 	status = "okay";
 };