clk: qcom: clk-rpm: Fix clk_hw references

Fix the clk_hw references to the actual clocks and add a xlate function
to return the hw pointers from the already existing static array.

Reported-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>