cpufreq: Enable big.LITTLE cpufreq driver on arm64

There are arm64 big.LITTLE systems so enable the big.LITTLE cpufreq driver.
While IKS is not available for these systems the driver is still useful
since it manages clusters with shared frequencies which is the common case
for these systems.

Long term combining the cpufreq-cpu0 and big.LITTLE drivers may be a
more sensible option but that is substantially more complex especially
in the case of IKS.

Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/Kconfig.arm

@@ -5,7 +5,8 @@
 # big LITTLE core layer and glue drivers
 config ARM_BIG_LITTLE_CPUFREQ
 	tristate "Generic ARM big LITTLE CPUfreq driver"
-	depends on ARM && BIG_LITTLE && ARM_CPU_TOPOLOGY && HAVE_CLK
+	depends on (BIG_LITTLE && ARM_CPU_TOPOLOGY) || (ARM64 && SMP)
+	depends on HAVE_CLK
 	select PM_OPP
 	help
 	  This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.