Complete vnd7050aj module integration

- Move DTS binding from project root to module folder
- Update module.yml to use correct dts_root path
- Restructure module for better organization and portability
- All module files now self-contained in modules/vnd7050aj/

Module structure:
- CMakeLists.txt: Uses zephyr_library for proper integration
- Kconfig: Module configuration options
- dts/bindings/: Device tree binding definitions
- include/: Public header files
- src/: Module source code
- zephyr/module.yml: Module discovery and configuration

Build verified successful on both x86 and ARM targets.

modules/vnd7050aj/dts/bindings/vnd7050aj.yaml

@@ -0,0 +1,22 @@
+description: STMicroelectronics VND7050AJ High-Side Driver
+
+compatible:
+  - st,vnd7050aj
+
+properties:
+  label:
+    type: string
+    required: true
+    description: Human readable name for the device
+
+  # Example property for a GPIO pin, adjust as needed
+  gpio-enable-pin:
+    type: phandle-array
+    required: true
+    description: GPIO pin for enabling the device
+
+  # Add other properties relevant to the VND7050AJ, e.g.,
+  # current-sense-gpios:
+  #   type: phandle-array
+  #   required: false
+  #   description: GPIO pins for current sensing