clk: qcom: Add HFPLL driver

On some devices (MSM8974 for example), the HFPLLs are
instantiated within the Krait processor subsystem as separate
register regions. Add a driver for these PLLs so that we can
provide HFPLL clocks for use by the system.

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>