cpufreq: qcom: Update the bandwidth levels on frequency change

Add support to parse optional OPP table attached to the cpu node when
the OPP bandwidth values are populated. This allows for scaling of
DDR/L3 bandwidth levels with frequency change.

Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>