cpufreq: qcom-cpufreq-hw: Simplify the boost frequency

Update the logic to handle multiple boost frequencies and also add the
frequencies to the OPP irrespective of normal or boost frequency.

Change-Id: I5b6dc8b157128392fd79e910c88911d6f4bd7b4d
Signed-off-by: Taniya Das <tdas@codeaurora.org>