cpufreq: CPPC: Don't set transition_latency

Now that the driver has started to set transition_delay_us directly,
there is no need to set transition_latency along with it, as it is not
used by the cpufreq core.

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