cpufreq: dt: Unsupported OPPs are already disabled

The core already have a valid regulator set for the device opp and the
unsupported OPPs are already disabled by the core. There is no need to
repeat that in the user drivers, get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>