Yc/playback fix

[yoelrc88]

• Added gitignore
• Increasing Kernel FIFO size
• Using FIFO declaration for fixed size data instead of dynamic.
• Fixed logic in matrixio_fifo_status.
• FIxed logic in thread_pcm_playback
• Returning buffer position as frames instead of bytes in matrixio_playback_pointer
• Cleaning and removing debug prints