lib: midi2: new UMP Stream responder library

Add a new top-level, transport independent library to respond to UMP Stream
Discovery messages. This allows MIDI2.0 clients to discover UMP endpoints
hosted on Zephyr over the UMP protocol.

The endpoint specification can be gathered from the device tree, so that
the same information used to generate USB descriptors in usb-midi2.0
can be delivered over UMP Stream.

Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>
9 files changed