cpufreq: arm_big_little: add vexpress SPC interface driver

The TC2(i.e. CA15_A7) Versatile Express has external Cortex M3 based
power controller which is responsible for CPU DVFS and SPC provides
the interface for the same.

This patch adds a tiny interface driver to check if OPPs are
initialised by SPC platform code and register the arm_big_little
cpufreq driver.

Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index b7948bb..7494565 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -74,6 +74,7 @@
 obj-$(CONFIG_ARM_SA1110_CPUFREQ)	+= sa1110-cpufreq.o
 obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA_CPUFREQ)		+= tegra-cpufreq.o
+obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
 
 ##################################################################################
 # PowerPC platform drivers