regulator: fan53555: Fix missing slew_reg/mask/shift settings for FAN53526

The di->slew_reg/di->slew_mask/di->slew_shift was not set in current code,
fix it.

Fixes: f2a9eb97 ("regulator: fan53555: Add support for FAN53526")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20210525124017.2550029-1-axel.lin@ingics.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/fan53555.c

@@ -296,6 +296,9 @@ static int fan53526_voltages_setup_fairchild(struct fan53555_device_info *di)
 		return -EINVAL;
 	}
 
+	di->slew_reg = FAN53555_CONTROL;
+	di->slew_mask = CTL_SLEW_MASK;
+	di->slew_shift = CTL_SLEW_SHIFT;
 	di->vsel_count = FAN53526_NVOLTAGES;
 
 	return 0;