cpufreq: Update sscanf() to kstrtouint()

cpufreq: Update sscanf() to kstrtouint()

In store_scaling_setspeed(), sscanf is still used to read to sysfs.
Newer kstrtox provide more features including overflow protection,
better errorhandling and allows for other systems of numeration. It
is therefore better to update sscanf() to kstrtouint().

Signed-off-by: Bowen Yu <yubowen8@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250519070938.931396-1-yubowen8@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>