[Ver 2.x] request to add either a Mix_LockAudio or a simple function Mix_GetAudioDeviceId

[Raffaello]

adding a Mix_GetAudioDeviceId allows to use SDL_LockAudioDevice

I can understand that allowing the device id outside the mixer can lead to programming errors.

Alternatively would it be possible to add Mix_LockAudioDevice (and the unlock part) ?

---

or probably the best choice would be:

would it make sense instead to return the device id from Mix_OpenAudioDevice (and Mix_OpenAudio) ?

---

Let me know if anything would make any sense to have that add on in the mixer.

p.s.
apologies if this might have been done for version 3 as i am still using 2.x