opp: Update the bandwidth on OPP frequency changes

If the OPP bandwidth values are populated, we want to switch also the
interconnect bandwidth in addition to frequency and voltage.

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