cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver

The CPUfreq HW present in some QCOM chipsets offloads the steps necessary
for changing the frequency of CPUs. The driver implements the cpufreq
driver interface for this hardware engine.

Change-Id: Ibf60ba171b4515c1f2f225ba4c9ed81094864ced
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Taniya Das <tdas@codeaurora.org>