cpufreq: s5pv210: use relaxed IO accesors

The use of __raw IO accesors is not endian safe and should be used
sparingly. The relaxed variants should be as lightweight and also
are endian safe.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>