Tab5 power expander driver and devicetree parsing improvements (#507)

* **New Features**
  * PI4IOE5V6408 I2C I/O expander driver with public GPIO APIs
  * CLI tool to list devicetree dependencies

* **Device Tree Updates**
  * M5Stack Tab5 configured with two I2C IO expanders; PI4IOE5V6408 binding added

* **Build / Tooling**
  * Devicetree code generation integrated into build; generated artifacts and dynamic dependency resolution exposed

* **Refactor**
  * Kernel/run APIs updated to accept a null‑terminated devicetree modules array; many module symbols renamed

* **Documentation**
  * Added README and Apache‑2.0 license for new driver module

Devices/m5stack-tab5/m5stack,tab5.dts

@@ -5,6 +5,7 @@
 #include <tactility/bindings/esp32_i2c.h>
 #include <tactility/bindings/esp32_i2s.h>
 #include <tactility/bindings/esp32_spi.h>
+#include <bindings/pi4ioe5v6408.h>
 
 / {
 	compatible = "root";
@@ -21,6 +22,36 @@
 		clock-frequency = <400000>;
 		pin-sda = <&gpio0 31 GPIO_FLAG_NONE>;
 		pin-scl = <&gpio0 32 GPIO_FLAG_NONE>;
+
+		/*
+		 - Bit 0: RF internal/external switch
+		 - Bit 1: Speaker enable
+		 - Bit 2: External 5V bus enable
+		 - Bit 3: /
+		 - Bit 4: LCD reset
+		 - Bit 5: Touch reset
+		 - Bit 6: Camera reset
+		 - Bit 7: Headphone detect
+		 */
+		io_expander0 {
+			compatible = "diodes,pi4ioe5v6408";
+			reg = <0x43>;
+		};
+
+		/*
+		 - Bit 0: C6 WLAN enable
+		 - Bit 1: /
+		 - Bit 2: /
+		 - Bit 3: USB-A 5V enable
+		 - Bit 4: Device power: PWROFF_PLUSE
+		 - Bit 5: IP2326: nCHG_QC_EN
+		 - Bit 6: IP2326: CHG_STAT_LED
+		 - Bit 7: IP2326: CHG_EN
+		*/
+		io_expander1 {
+			compatible = "diodes,pi4ioe5v6408";
+			reg = <0x44>;
+		};
 	};
 
 	i2c_port_a: i2c1 {