cpufreq: dt: Tolerance applies on both sides of target voltage

commit a2022001 upstream.

Tolerance applies on both sides of the target voltage, i.e. both min and
max sides. But while checking if a voltage is supported by the regulator
or not, we haven't taken care of tolerance on the lower side. Fix that.

Cc: Lucas Stach <l.stach@pengutronix.de>
Fixes: 045ee45c ("cpufreq: cpufreq-dt: disable unsupported OPPs")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/cpufreq/cpufreq-dt.c

@@ -255,7 +255,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 			rcu_read_unlock();
 
 			tol_uV = opp_uV * priv->voltage_tolerance / 100;
-			if (regulator_is_supported_voltage(cpu_reg, opp_uV,
+			if (regulator_is_supported_voltage(cpu_reg,
+							   opp_uV - tol_uV,
 							   opp_uV + tol_uV)) {
 				if (opp_uV < min_uV)
 					min_uV = opp_uV;