pinctrl: pinconf: take the right mutex

The pinconf_dgb_config_print() takes the per-pincontroller
mutex, when what it wants to take is actually the pin maps
mutex.

Reported-by: James Hogan <[e-mail]>
Cc: Patrice Chotard <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/pinconf.c

···
 	bool found = false;
 	unsigned long config;
 
-	mutex_lock(&pctldev->mutex);
+	mutex_lock(&pinctrl_maps_mutex);
 
 	/* Parse the pinctrl map and look for the elected pin/state */
 	for_each_maps(maps_node, i, map) {
···
 		confops->pin_config_config_dbg_show(pctldev, s, config);
 
 exit:
-	mutex_unlock(&pctldev->mutex);
+	mutex_unlock(&pinctrl_maps_mutex);
 
 	return 0;
 }