ALSA: usb-audio: remove Wireless USB dead code

ALSA: usb-audio: remove Wireless USB dead code

Wireless USB host controller support has been removed
from Linux Kernel more than 3 years ago in commit
caa6772db4c1 ("Staging: remove wusbcore and UWB from the
kernel tree."), and the associated code in the
snd-usb-audio driver became unused and untested.

If in the future somebody will return WUSB/UWB support
back to the kernel, the snd-usb-audio driver will reject
Wireless USB audio devices at probe stage, and this patch
should be reverted.

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Link: https://lore.kernel.org/r/20230312222857.296623-1-ruslan.bilovol@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>