usb_audio: Disable for 2.0 devices.

It does not seem to work and causes high CPU usage.

usb_audio: Do not use any timeout in _MultiBufferExchange.

The other multi-audio drivers do likewise.

Add missing NULL checks to USB drivers.

Should fix #17276, #17846.

usb_audio: Yet more code cleanup.

Slight logic tweaks but no real behavioral changes intended.

usb_audio: Correct mixup between Input terminals and Input streams.

An "Input" terminal in USB audio terms refers to any stream of audio
going "in" to the USB device, whether that be from the outside world
(e.g. a line in jack) or from the computer (e.g. via USB OUT endpoints.)

So we cannot rely on the terminal type to tell us whether it is an in
or an out for our purposes, we have to check the stream type, and then
use that to declare to multi_audio what kind of stream we have.

Fixes USB audio mixing up inputs and outputs, especially on devices
that only have one or the other and not both. (QEMU manifested
this problem.)

usb_audio: Code cleanup.

No functional changes intended.

usb_audio: Stop before reallocating buffers and add more error checks.

Also print strerror() for SetGlobalFormat.

usb_audio: Fixes for SMAP.

usb_audio: use user_memcpy to read/write the user buffers.

* also check buffer addresses passed through structures.
* fixes gcc5 and 64-bit warnings.
* only setup tested (lack of isochronous transfers).

Rename driver folder 'usb_audio' to 'usb'

... just because the source path ./kernel/drivers/audio/usb obviously
references audio hardware so "_audio" suffix is excessive.

No functional changes.

Rename driver folder 'usb_audio' to 'usb'

... just because the source path ./kernel/drivers/audio/usb obviously
references audio hardware so "_audio" suffix is excessive.

No functional changes.