ALSA: usb-audio: Fix mixer regression on SteelSeries Arctis Nova 5

ALSA: usb-audio: Fix mixer regression on SteelSeries Arctis Nova 5

The recent "sticky mixer" sanity check in USB-audio driver caused a
regression on SteelSeries Arctis Nova 5 (1038:2232); because the
firmware doesn't handle GET_CUR requests, some mixers are effectively
disabled, leading to the too low / soft volumes:
  usb 5-1.1: 9:0: sticky mixer values (-19712/0/256 => 0), disabling
  usb 5-1.1: 10:0: sticky mixer values (-21248/0/256 => 0), disabling

Restore the functionality by ignoring GET_CUR errors intentionally
with MIXER_GET_CUR_BROKEN quirk.

Fixes: 86aa1ea1f15c ("ALSA: usb-audio: Do not expose sticky mixers")
Reported-by: Gert Burger <gertburger@gmail.com>
Closes: https://lore.kernel.org/CAEQ1D3kdA3mkQx7ei9Kq0gwky0qroJqCLKrkvgfkqgTbeu086A@mail.gmail.com
Link: https://bbs.archlinux.org/viewtopic.php?id=314220
Link: https://patch.msgid.link/20260808152258.1948767-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>