arm64: dts: qcom: msm8998: Add blsp1_uart3

The blsp1_uart3 peripheral appears to be commonly used for interfacing with
other SoCs on a platform, such as a wcn3990 to provide bluetooth.
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/msm8998-pins.dtsi

@@ -75,4 +75,17 @@ config {
 			drive-strength = <2>;   /* 2 mA */
 		};
 	};
+
+	blsp1_uart3_on: blsp1_uart3_on {
+		mux {
+			pins = "gpio45", "gpio46", "gpio47", "gpio48";
+			function = "blsp_uart3_a";
+		};
+
+		config {
+			pins = "gpio45", "gpio46", "gpio47", "gpio48";
+			drive-strength = <2>;
+			bias-disable;
+		};
+	};
 };

arch/arm64/boot/dts/qcom/msm8998.dtsi

@@ -1569,6 +1569,20 @@ blsp1_dma: dma@c144000 {
 			qcom,num-ees = <4>;
 		};
 
+		blsp1_uart3: serial@c171000 {
+			compatible = "qcom,msm-uartdm-v1.4", "qcom,msm-uartdm";
+			reg = <0x0c171000 0x1000>;
+			interrupts = <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&gcc GCC_BLSP1_UART3_APPS_CLK>,
+				 <&gcc GCC_BLSP1_AHB_CLK>;
+			clock-names = "core", "iface";
+			dmas = <&blsp1_dma 4>, <&blsp1_dma 5>;
+			dma-names = "tx", "rx";
+			pinctrl-names = "default";
+			pinctrl-0 = <&blsp1_uart3_on>;
+			status = "disabled";
+		};
+
 		blsp1_i2c1: i2c@c175000 {
 			compatible = "qcom,i2c-qup-v2.2.1";
 			reg = <0x0c175000 0x600>;