power: supply: core: use device mutex wrappers

The mutex is an implementation detail of struct device.
Use the dedicated wrappers to access the field.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/power_supply_core.c

···
 						deferred_register_work.work);
 
 	if (psy->dev.parent) {
-		while (!mutex_trylock(&psy->dev.parent->mutex)) {
+		while (!device_trylock(psy->dev.parent)) {
 			if (psy->removing)
 				return;
 			msleep(10);
···
 	power_supply_changed(psy);
 
 	if (psy->dev.parent)
-		mutex_unlock(&psy->dev.parent->mutex);
+		device_unlock(psy->dev.parent);
 }
 
 #ifdef CONFIG_OF