cpufreq: fix EXYNOS drivers selection

* remove superfluous pr_debug() call from exynos_cpufreq_init()
  (init errors are always logged anyway)
* add dummy per-SoC type init functions to exynos-cpufreq.h
* make per-SoC type cpufreq config options selectable
* make CONFIG_ARM_EXYNOS_CPUFREQ config option invisible to user and
  automatically enable it when needed

This patch fixes following issues:
* EXYNOS per-SoC type cpufreq support (i.e. exynos4210-cpufreq.c) being
  always built if given SoC support was enabled (i.e. CPU_EXYNOS4210),
  even if common EXYNOS cpufreq support was disabled
* inability to select cpufreq for each SoC type separately (it could
  be only enabled/disabled for all SoCs for which support was enabled)
* EXYNOS5440 cpufreq support was always enabled when EXYNOS5440
  support was enabled and couldn't be disabled

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index de4d5d9..0fa204b 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -17,37 +17,47 @@
 	  big.LITTLE platform. This gets frequency tables from DT.
 
 config ARM_EXYNOS_CPUFREQ
-	bool "SAMSUNG EXYNOS SoCs"
-	depends on ARCH_EXYNOS
+	bool
 	select CPU_FREQ_TABLE
-	default y
-	help
-	  This adds the CPUFreq driver common part for Samsung
-	  EXYNOS SoCs.
-
-	  If in doubt, say N.
 
 config ARM_EXYNOS4210_CPUFREQ
-	def_bool CPU_EXYNOS4210
+	bool "SAMSUNG EXYNOS4210"
+	depends on CPU_EXYNOS4210
+	default y
+	select ARM_EXYNOS_CPUFREQ
 	help
 	  This adds the CPUFreq driver for Samsung EXYNOS4210
 	  SoC (S5PV310 or S5PC210).
 
+	  If in doubt, say N.
+
 config ARM_EXYNOS4X12_CPUFREQ
-	def_bool (SOC_EXYNOS4212 || SOC_EXYNOS4412)
+	bool "SAMSUNG EXYNOS4x12"
+	depends on (SOC_EXYNOS4212 || SOC_EXYNOS4412)
+	default y
+	select ARM_EXYNOS_CPUFREQ
 	help
 	  This adds the CPUFreq driver for Samsung EXYNOS4X12
 	  SoC (EXYNOS4212 or EXYNOS4412).
 
+	  If in doubt, say N.
+
 config ARM_EXYNOS5250_CPUFREQ
-	def_bool SOC_EXYNOS5250
+	bool "SAMSUNG EXYNOS5250"
+	depends on SOC_EXYNOS5250
+	default y
+	select ARM_EXYNOS_CPUFREQ
 	help
 	  This adds the CPUFreq driver for Samsung EXYNOS5250
 	  SoC.
 
+	  If in doubt, say N.
+
 config ARM_EXYNOS5440_CPUFREQ
-	def_bool SOC_EXYNOS5440
+	bool "SAMSUNG EXYNOS5440"
+	depends on SOC_EXYNOS5440
 	depends on HAVE_CLK && PM_OPP && OF
+	default y
 	select CPU_FREQ_TABLE
 	help
 	  This adds the CPUFreq driver for Samsung EXYNOS5440
@@ -55,6 +65,8 @@
 	  different than previous exynos controllers so not using
 	  the common exynos framework.
 
+	  If in doubt, say N.
+
 config ARM_HIGHBANK_CPUFREQ
 	tristate "Calxeda Highbank-based"
 	depends on ARCH_HIGHBANK