boards: alif: alif_b1_dk: Add common DTSI files for both SoC series

Add the common DTSI includes for the two supported SoC series:

1. alif_b1_dk_ab1c1f1m41820xx0_rtss_he.dtsi
2. alif_b1_dk_ab1c1f4m51820xx0_rtss_he.dtsi

These files contain shared definitions used across both variants.

Signed-off-by: Prabhakar Kumar <prabhakar.kumar@alifsemi.com>

Author: Prabhakar-Alifsemi

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f1m41820hh0_rtss_he.dts

@@ -7,6 +7,7 @@
 
 #include <alif/balletto/b1/ab1c1f1m41820hh0.dtsi>
 #include "../common/balletto-pinctrl.dtsi"
+#include "alif_b1_dk_ab1c1f1m41820xx0_rtss_he.dtsi"
 
 / {
 	compatible = "arm,alif-b1-dk-ab1c1f1m41820hh0-rtss-he";
@@ -50,3 +51,7 @@
 &gpio4 {
 	status = "okay";
 };
+
+&gpio5 {
+	status = "okay";
+};

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f1m41820ph0_rtss_he.dts

@@ -7,6 +7,7 @@
 
 #include <alif/balletto/b1/ab1c1f1m41820ph0.dtsi>
 #include "../common/balletto-pinctrl.dtsi"
+#include "alif_b1_dk_ab1c1f1m41820xx0_rtss_he.dtsi"
 
 / {
 	compatible = "arm,alif-b1-dk-ab1c1f1m41820ph0-rtss-he";
@@ -50,3 +51,7 @@
 &gpio4 {
 	status = "okay";
 };
+
+&gpio5 {
+	status = "okay";
+};

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f1m41820xx0_rtss_he.dtsi

@@ -0,0 +1,41 @@
+/* Copyright (c) 2025 Alif Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&{/} {
+	chosen {
+		zephyr,console = &uart2;
+		zephyr,shell-uart = &uart2;
+	};
+
+	aliases {
+		led0 = &aled0;
+		sw0 = &button0;
+		watchdog0 = &wdog0;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		aled0: led_0 {
+			gpios = <&gpio4 5 0>;
+			label = "LED0_G";
+		};
+	};
+
+	buttons {
+		compatible = "gpio-keys";
+		button0: button_0 {
+			gpios = <&gpio5 7 0>;
+			label = "SW0";
+		};
+	};
+};
+
+&uart2 {
+	status = "okay";
+};
+
+&gpio4 {
+	status = "okay";
+};

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f4m51820hh0_rtss_he.dts

@@ -7,6 +7,7 @@
 
 #include <alif/balletto/b1/ab1c1f4m51820hh0.dtsi>
 #include "../common/balletto-pinctrl.dtsi"
+#include "alif_b1_dk_ab1c1f4m51820xx0_rtss_he.dtsi"
 
 / {
 	compatible = "arm,alif-b1-dk-ab1c1f4m51820hh0-rtss-he";

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f4m51820ph0_rtss_he.dts

@@ -7,6 +7,7 @@
 
 #include <alif/balletto/b1/ab1c1f4m51820ph0.dtsi>
 #include "../common/balletto-pinctrl.dtsi"
+#include "alif_b1_dk_ab1c1f4m51820xx0_rtss_he.dtsi"
 
 / {
 	compatible = "arm,alif-b1-dk-ab1c1f4m51820ph0-rtss-he";

boards/alif/alif_b1_dk/alif_b1_dk_ab1c1f4m51820xx0_rtss_he.dtsi

@@ -0,0 +1,73 @@
+/* Copyright (c) 2025 Alif Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&{/} {
+	chosen {
+		zephyr,console = &uart2;
+		zephyr,shell-uart = &uart2;
+		zephyr,bt-hci = &alif_hci_uart;
+		zephyr,hci-uart = &uart_hci;
+		zephyr,uart-mcumgr = &uart2;
+		zephyr,entropy = &rng;
+	};
+
+	aliases {
+		led0 = &aled0;
+		sw0 = &button0;
+		watchdog0 = &wdog0;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		aled0: led_0 {
+			gpios = <&gpio4 5 0>;
+			label = "LED0_G";
+		};
+	};
+
+	buttons {
+		compatible = "gpio-keys";
+
+		button0: button_0 {
+			gpios = <&gpio5 7 0>;
+			label = "SW0";
+		};
+	};
+};
+
+&uart2 {
+	status = "okay";
+};
+
+&uart_hci {
+	clock-frequency = <160000000>;
+	dmas = <&dma2 HCI_UART_DMA_RX_CH HCI_UART_DMA_RX_REQ>,
+	       <&dma2 HCI_UART_DMA_TX_CH HCI_UART_DMA_TX_REQ>;
+	dma-names = "rx", "tx";
+	status = "okay";
+};
+
+&uart_ahi {
+	clock-frequency = <160000000>;
+	pinctrl-0 = <&pinctrl_ahi_trace>;
+	pinctrl-names = "default";
+	dmas = <&dma2 AHI_UART_DMA_RX_CH AHI_UART_DMA_RX_REQ>,
+	       <&dma2 AHI_UART_DMA_TX_CH AHI_UART_DMA_TX_REQ>;
+	dma-names = "rx", "tx";
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
+&gpio4 {
+	status = "okay";
+};
+
+&gpio5 {
+	status = "okay";
+};