This is the very first step for merging the `mmdevdrv.c` files into a single one.
The commit strictly focuses on Linux drivers, `wine{oss,coreaudio}` will follow.
Huge thanks to @jacek and @huw for making this simple, as they took care of ELF/PE separation.
-- v4: winepulse: Switch to mmdevapi's unixlib.h winepulse: Adapt "get_prop_value_params" struct to mmdevapi's winepulse: Adapt "is_started_params" struct to mmdevapi's winepulse: Adapt "get_device_period_params" struct to mmdevapi's winepulse: Adapt "get_mix_format_params" struct to mmdevapi's winepulse: Adapt "get_capture_buffer_params" struct to mmdevapi's winepulse: Adapt "release_render_buffer_params" struct to mmdevapi's winepulse: Adapt "release_stream_params" struct to mmdevapi's winepulse: Adapt "create_stream_params" struct to mmdevapi's winepulse: Adapt "endpoint" struct to mmdevapi's mmdevapi: Integrate winepulse's additions in unixlib.h winealsa: Move common unixlib.h content into mmdevapi winealsa: Drop "alsa_" prefix in unixlib enum, apply it to the functions instead