cpufreq: exynos: Use static for functions used in only this file

Fixes following sparse error.
drivers/cpufreq/exynos-cpufreq.c:34:5: warning: symbol
'exynos_verify_speed' was not declared. Should it be static?
drivers/cpufreq/exynos-cpufreq.c:40:14: warning: symbol
'exynos_getspeed' was not declared. Should it be static?

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/exynos-cpufreq.c

@@ -31,13 +31,13 @@ static unsigned int locking_frequency;
 static bool frequency_locked;
 static DEFINE_MUTEX(cpufreq_lock);
 
-int exynos_verify_speed(struct cpufreq_policy *policy)
+static int exynos_verify_speed(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy,
 					      exynos_info->freq_table);
 }
 
-unsigned int exynos_getspeed(unsigned int cpu)
+static unsigned int exynos_getspeed(unsigned int cpu)
 {
 	return clk_get_rate(exynos_info->cpu_clk) / 1000;
 }