Reusable BSP Framework (Repository Reorganization & Shared Build Infrastructure

[AmmarOkla12772]

Begin the reusable BSP framework by reorganizing the repository into a common multi-board layout and centralizing shared build infrastructure. This establishes the foundation for future board ports and shared applications.

Goals:

• Create a common targets/ directory for board implementations.
• Centralize shared CMake modules under the repository root.
• Create shared apps/, bsp_interface/, and target template directories.
• Move existing board implementations into the new directory structure.
• Update existing targets to build using the centralized CMake configuration.

DoD:

• Existing boards build successfully after the repository reorganization.
• Shared CMake modules are used by all targets.
• Standard directory structure is established for future board onboarding.