Improve kmutex implementation

[pbalduino]

Goal

Enhance the existing kmutex implementation to be more robust, efficient, and feature-complete for kernel synchronization.

Context

The current kmutex implementation provides basic mutual exclusion but could benefit from improvements in performance, debugging capabilities, and additional features needed for a robust kernel synchronization primitive.

Definition of Done

• Performance improvements: Optimize lock/unlock operations for minimal overhead
• Debugging support: Add lock tracking, deadlock detection, and ownership validation
• Priority handling: Implement priority inheritance to prevent priority inversion
• Timeout support: Add kmutex_lock_timeout() for non-blocking operations with timeouts
• Recursive locks: Support for recursive mutex acquisition by the same thread
• Error handling: Improve error reporting and validation of mutex operations
• Statistics: Add lock contention statistics and performance monitoring
• Documentation: Comprehensive API documentation with usage examples

Potential Improvements

• Add kmutex_trylock() for non-blocking lock attempts
• Implement fair scheduling to prevent lock starvation
• Add mutex debugging modes (leak detection, double-lock detection)
• Support for different mutex types (normal, recursive, errorcheck)
• Integration with kernel debugging and profiling tools
• Lock ordering validation to detect potential deadlocks