dm: power: Use debug() for errors in regulator uclass

To reduce unnecessary code size in an uncommon code path, use debug()
where possible(). The driver returns an error which indicates failure.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

drivers/power/regulator/regulator-uclass.c

@@ -262,7 +262,7 @@ static int regulator_post_bind(struct udevice *dev)
 	if (regulator_name_is_unique(dev, uc_pdata->name))
 		return 0;
 
-	error("\"%s\" of dev: \"%s\", has nonunique value: \"%s\"",
+	debug("\"%s\" of dev: \"%s\", has nonunique value: \"%s\"",
 	      property, dev->name, uc_pdata->name);
 
 	return -EINVAL;