regulator: max8973: Remove unused field from 'struct max8973_chip'

The 'struct regulator_dev *rdev' of 'struct max8973_chip' isn't used
anywhere in the driver so it can be removed safely.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/max8973-regulator.c

···
 struct max8973_chip {
 	struct device *dev;
 	struct regulator_desc desc;
-	struct regulator_dev *rdev;
 	struct regmap *regmap;
 	bool enable_external_control;
 	int dvs_gpio;
···
 		return ret;
 	}
 
-	max->rdev = rdev;
 	return 0;
 }