cpufreq: ARM big LITTLE: Select PM_OPP

The ARM big LITTLE cpufreq driver uses the OPP layer for its
functionality. Select it in Kconfig.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/Kconfig.arm

@@ -5,6 +5,7 @@
 config ARM_BIG_LITTLE_CPUFREQ
 	tristate
 	depends on ARM_CPU_TOPOLOGY
+	select PM_OPP
 
 config ARM_DT_BL_CPUFREQ
 	tristate "Generic ARM big LITTLE CPUfreq driver probed via DT"