[CPUFREQ] EXYNOS: Make EXYNOS common cpufreq driver

To support various EXYNOS series SoCs commonly,
added exynos common structure.
exynos-cpufreq.c => EXYNOS series common cpufreq driver
exynos4210-cpufreq.c => EXYNOS4210 support cpufreq driver

Signed-off-by: Jaecheol Lee <jc.lee@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>

drivers/cpufreq/Kconfig.arm

@@ -21,12 +21,19 @@ config ARM_S5PV210_CPUFREQ
 
 	  If in doubt, say N.
 
+config ARM_EXYNOS_CPUFREQ
+	bool "SAMSUNG EXYNOS SoCs"
+	depends on ARCH_EXYNOS
+	select ARM_EXYNOS4210_CPUFREQ if CPU_EXYNOS4210
+	default y
+	help
+	  This adds the CPUFreq driver common part for Samsung
+	  EXYNOS SoCs.
+
+	  If in doubt, say N.
+
 config ARM_EXYNOS4210_CPUFREQ
 	bool "Samsung EXYNOS4210"
-	depends on CPU_EXYNOS4210
-	default y
 	help
 	  This adds the CPUFreq driver for Samsung EXYNOS4210
 	  SoC (S5PV310 or S5PC210).
-
-	  If in doubt, say N.