opp: ti-opp-supply: Correct the supply in _get_optimal_vdd_voltage call

_get_optimal_vdd_voltage call provides new_supply_vbb->u_volt
as the reference voltage while it should be really new_supply_vdd->u_volt.

Cc: 4.16+ <stable@vger.kernel.org> # v4.16+
Fixes: 9a835fa6e47 ("PM / OPP: Add ti-opp-supply driver")
Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/opp/ti-opp-supply.c

@@ -288,7 +288,7 @@ static int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
 	int ret;
 
 	vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
-					  new_supply_vbb->u_volt);
+					  new_supply_vdd->u_volt);
 
 	if (new_supply_vdd->u_volt_min < vdd_uv)
 		new_supply_vdd->u_volt_min = vdd_uv;