ALSA: hda: Fix a regression in Capture Switch mixer read

The recent commit to drop the HDA-specific mute-LED control,
e65bf997 ("ALSA: HDA - remove the custom implementation for the
audio LED trigger"), caused a regression on the mixer element read for
"Capture Switch" when it's built from bind controls.  The function
create_bind_cap_vol_ctl() creates the snd_kcontrol_new object directly
via snd_hda_gen_add_kctl() instead of add_control().  Although the
commit above added a workaround for the SNDRV_CTL_ACCESS_READWRITE in
add_control() as default, this code path fell out from the radar.  As
a result, now the driver gives -EPERM error because of the lack of the
proper access bit at reading "Capture Switch" element value.

Fix the regression by setting the access bit properly.

Fixes: e65bf997 ("ALSA: HDA - remove the custom implementation for the audio LED trigger")
BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1186634
Link: https://lore.kernel.org/r/20210531180633.27831-1-tiwai@suse.de


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