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

TactilityKernel/include/tactility/kernel_init.h

@@ -1,21 +1,20 @@
 #pragma once
 
+#include <tactility/dts.h>
+#include <tactility/error.h>
+#include <tactility/module.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#include <tactility/device.h>
-#include <tactility/error.h>
-#include <tactility/module.h>
-
 /**
- * Initialize the kernel with platform and device modules, and a device tree.
- * @param platform_module The platform module to start. This module should not be constructed yet.
- * @param device_module The device module to start. This module should not be constructed yet. This parameter can be NULL.
- * @param dts_devices The list of generated devices from the devicetree. The array must be terminated with DTS_DEVICE_TERMINATOR. This parameter can be NULL.
+ * Initialize the kernel with the provided modules from the device tree
+ * @param dts_modules List of modules from devicetree, null-terminated. Non-null parameter.
+ * @param dts_devices The list of generated devices from the devicetree. The array must be terminated with DTS_DEVICE_TERMINATOR. Non-null parameter.
  * @return ERROR_NONE on success, otherwise an error code
  */
-error_t kernel_init(struct Module* platform_module, struct Module* device_module, struct DtsDevice dts_devices[]);
+error_t kernel_init(struct Module* dts_modules[], struct DtsDevice dts_devices[]);
 
 #ifdef __cplusplus
 }

TactilityKernel/include/tactility/module.h

@@ -3,6 +3,7 @@
 
 #include "error.h"
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
 
 #ifdef __cplusplus