cpufreq: exynos: Add missing static

Add missing 'static' qualifiers.

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/drivers/cpufreq/exynos4210-cpufreq.c b/drivers/cpufreq/exynos4210-cpufreq.c
index 250dcf0..de91755 100644
--- a/drivers/cpufreq/exynos4210-cpufreq.c
+++ b/drivers/cpufreq/exynos4210-cpufreq.c
@@ -114,7 +114,7 @@
 	} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
 }
 
-bool exynos4210_pms_change(unsigned int old_index, unsigned int new_index)
+static bool exynos4210_pms_change(unsigned int old_index, unsigned int new_index)
 {
 	unsigned int old_pm = apll_freq_4210[old_index].mps >> 8;
 	unsigned int new_pm = apll_freq_4210[new_index].mps >> 8;