ALSA: usb-audio: Move ignore_ctl_error check into quirk_flags

The mixer code has a flag ignore_ctl_error for ignoring the errors
returned from the device wrt mixer accesses, and this is set from the
entries in mixer_maps.c, as well as ignore_ctl_error module option.
Those can be well integrated into the new quirk_flags field, too.

Link: https://lore.kernel.org/r/20210729074404.19728-3-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>