cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()

The cpufreq_driver->get() callback is supposed to return the current
frequency of the CPU and not the one requested by the CPUFreq core.
Fix it by returning the frequency that gets supplied to the CPU after
the DCVS operation of EPSS/OSM.

Fixes: 2849dd8b

 ("cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver")
Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>