OPP: Extend dev_pm_opp_data with turbo support

Let's extend the dev_pm_opp_data with a turbo variable, to allow users to
specify if it's a boost frequency for a dynamically added OPP.

Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>