Refactor board files to match standard naming convention

- Rename WaveshareEsp32C6Lcd147.cpp to Configuration.cpp
- Remove unused WaveshareEsp32C6Lcd147.h header file

This aligns the board implementation with other boards in the codebase,
which use Configuration.cpp as the standard name for the board
configuration file.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: marciogranzotto