cpufreq: introduce cpufreq_generic_get() routine

CPUFreq drivers that use clock frameworks interface,i.e. clk_get_rate(),
to get CPUs clk rate, have similar sort of code used in most of them.

This patch adds a generic ->get() which will do the same thing for them.
All those drivers are required to now is to set .get to cpufreq_generic_get()
and set their clk pointer in policy->clk during ->init().

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 2938257..ce69059 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -38,11 +38,6 @@
 static u32 *imx6_soc_volt;
 static u32 soc_opp_count;
 
-static unsigned int imx6q_get_speed(unsigned int cpu)
-{
-	return clk_get_rate(arm_clk) / 1000;
-}
-
 static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 {
 	struct dev_pm_opp *opp;
@@ -139,6 +134,7 @@
 
 static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 {
+	policy->clk = arm_clk;
 	return cpufreq_generic_init(policy, freq_table, transition_latency);
 }
 
@@ -146,7 +142,7 @@
 	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify = cpufreq_generic_frequency_table_verify,
 	.target_index = imx6q_set_target,
-	.get = imx6q_get_speed,
+	.get = cpufreq_generic_get,
 	.init = imx6q_cpufreq_init,
 	.exit = cpufreq_generic_exit,
 	.name = "imx6q-cpufreq",