ALSA: hda: Disable regmap internal locking

Since we apply the own mutex (bus->cmd_mutex) in HDA core side, the
internal locking in regmap is superfluous.  This patch adds the flag
to indicate that.

Also, an infamous side-effect by this change is that it disables the
regmap debugfs, too, and this is seen rather good; the regmap debugfs
isn't quite useful for HD-audio as it provides the very sparse
registers and its debugfs access tends to lead to the way too high
resource usages or sometimes hang up.  So it'd be rather safe to
disable it altogether.

Link: https://lore.kernel.org/r/2029139028.10333037.1572874551626.JavaMail.zimbra@redhat.com
Link: https://lore.kernel.org/r/20191105081806.4896-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/hdac_regmap.c

@@ -363,6 +363,7 @@ static const struct regmap_config hda_regmap_cfg = {
 	.reg_write = hda_reg_write,
 	.use_single_read = true,
 	.use_single_write = true,
+	.disable_locking = true,
 };
 
 /**