cpufreq: st: Provide runtime initialised driver for ST's platforms

The bootloader is charged with the responsibility to provide platform
specific Dynamic Voltage and Frequency Scaling (DVFS) information via
Device Tree.  This driver takes the supplied configuration and
registers it with the new generic OPP framework, to then be used with
CPUFreq.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 80fbfb3..ff9be36 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -219,6 +219,16 @@
 	help
 	  This adds the CPUFreq driver support for SPEAr SOCs.
 
+config ARM_STI_CPUFREQ
+	tristate "STi CPUFreq support"
+	depends on SOC_STIH407
+	help
+	  This driver uses the generic OPP framework to match the running
+	  platform with a predefined set of suitable values.  If not provided
+	  we will fall-back so safe-values contained in Device Tree.  Enable
+	  this config option if you wish to add CPUFreq support for STi based
+	  SoCs.
+
 config ARM_TEGRA20_CPUFREQ
 	bool "Tegra20 CPUFreq support"
 	depends on ARCH_TEGRA