regulator: aat2870: Don't explicitly initialise the first field

Doing so generates a warning as the first field is a pointer but we use
0 to initalize it.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/aat2870-regulator.c

@@ -162,7 +162,7 @@ static struct aat2870_regulator *aat2870_get_regulator(int id)
 static int aat2870_regulator_probe(struct platform_device *pdev)
 {
 	struct aat2870_regulator *ri;
-	struct regulator_config config = { 0 };
+	struct regulator_config config = { };
 	struct regulator_dev *rdev;
 
 	ri = aat2870_get_regulator(pdev->id);