cpufreq: Change default transition delay to 2ms

10ms is too high for today's hardware, even low end ones. This default
end up being used a lot on Arm machines at least. Pine64, mac mini and
pixel 6 all end up with 10ms rate_limit_us when using schedutil, and
it's too high for all of them.

Change the default to 2ms which should be 'pessimistic' enough for worst
case scenario, but not too high for platforms with fast DVFS hardware.

Signed-off-by: Qais Yousef <qyousef@layalina.io>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>