regulator: s2mpa01: Don't check enable_shift before setting enable ramp rate

Current code misses updating the register when enable_shift is 0.
e.g. S2MPA01_BUCK4_RAMP_EN_SHIFT is 0.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/regulator/s2mpa01.c

@@ -192,14 +192,12 @@ static int s2mpa01_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 	if (!ramp_enable)
 		goto ramp_disable;
 
-	if (enable_shift) {
 	ret = regmap_update_bits(rdev->regmap, S2MPA01_REG_RAMP1,
 				 1 << enable_shift, 1 << enable_shift);
 	if (ret) {
 		dev_err(&rdev->dev, "failed to enable ramp rate\n");
 		return ret;
 	}
-	}
 
 	ramp_val = get_ramp_delay(ramp_delay);