ALSA: usb-audio: Get UMP EP name string from USB interface

ALSA: usb-audio: Get UMP EP name string from USB interface

USB descriptor may provide a nicer name for USB interface, and we may
take it as the UMP Endpoint name.  The UMP EP name is copied as the
rawmidi name, too.

Also, fill the UMP block product_id field from the iSerialNumber
string of the USB device descriptor as a recommended unique id, too.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-11-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>