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/Kconfig

@@ -0,0 +1,5 @@
+config VND7050AJ
+	bool "VND7050AJ library support"
+	default n
+	help
+	  Enable support for the VND7050AJ high-side driver.