ARM: dts: stm32: Enable Bluetooth on AV96

The WiFi/Bluetooth chip is attached to USART2 on AV96 as well, describe
it in DT to make it available. Remove BT LED and turn it into a shutdown
GPIO, because the GPIO line controls the BT_REG_ON signal. The LED is just
an indicator connected to the same line, but not the primary function.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp157a-avenger96.dts

@@ -21,6 +21,7 @@
 		mmc0 = &sdmmc1;
 		serial0 = &uart4;
 		serial1 = &uart7;
+		serial2 = &usart2;
 		spi0 = &qspi;
 	};
 
@@ -63,13 +64,6 @@
 			default-state = "off";
 			panic-indicator;
 		};
-
-		led5 {
-			label = "blue:bt";
-			gpios = <&gpioz 6 GPIO_ACTIVE_HIGH>;
-			linux,default-trigger = "bluetooth-power";
-			default-state = "off";
-		};
 	};
 
 	sd_switch: regulator-sd_switch {
@@ -419,3 +413,18 @@
 	pinctrl-0 = <&uart7_pins_a>;
 	status = "okay";
 };
+
+/* Bluetooth */
+&usart2 {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&usart2_pins_a>;
+	pinctrl-1 = <&usart2_sleep_pins_a>;
+	st,hw-flow-ctrl;
+	status = "okay";
+
+	bluetooth {
+		compatible = "brcm,bcm43438-bt";
+		max-speed = <3000000>;
+		shutdown-gpios = <&gpioz 6 GPIO_ACTIVE_HIGH>;
+	};
+};