ALSA: usb-audio: Skip clock selector for Focusrite devices

ALSA: usb-audio: Skip clock selector for Focusrite devices

Add QUIRK_FLAG_SKIP_CLOCK_SELECTOR for Focusrite devices.

During interface parsing, snd_usb_clock_find_source() reads the clock
selector value then writes it back unchanged. On Focusrite devices
this redundant write results in a ~300ms delay per altsetting, adding
~1.8s to probe time on a typical device with 6 altsettings.

Enabling SKIP_CLOCK_SELECTOR skips the redundant write-back.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/00e53ae0a508b41516b41833daa17823381a649c.1771594828.git.g@b4.vu