Generic Test Infrastructure with Multi-Cluster Support

[Xeratec]

Changelog

This PR introduces a generic test infrastructure with interrupt-based printf support and multi-cluster testing capabilities, along with utility functions for the Snitch cluster runtime.

Added

• Generic test infrastructure in targets/chimera-convolve/ with interrupt-based printf support
• FLL (Frequency Locked Loop) support in host runtime (host/runtime/inc/fll.h, host/runtime/src/fll.c)
• CLINT utility functions for interrupt management (host/runtime/inc/clint.h, host/runtime/src/clint.c)
• Multi-cluster test support with improved abstraction layer

Changed

• Refactored test infrastructure to support multiple clusters simultaneously
• Updated all Snitch cluster tests (matmul, simpleOffload, snrt) to use the new generic test infrastructure
• Updated crt0.S startup code across multiple targets (chimera-convolve, chimera-host, chimera-open)
• Downgrade CMake Version for Ubuntu compatibility

Fixed

• Improved test abstraction and consistency across different cluster configurations
• Better interrupt handling and printf functionality in test environment

Checklist

1. The PR is rebased on the latest devel commit and pointing to devel.
2. Your PR reviewed and approved.
3. The documentation is updated.
4. All checks are passing.

[viv-eth]

Thank you for your contributions @Xeratec ! Nothing major, just some clarification requested.