cpufreq: amd-pstate: update pstate frequency transition delay time

Change the default transition latency to be 20ms that is more
reasonable transition delay for AMD processors in non-EPP driver mode.

Update transition delay time to 1ms, in the AMD CPU autonomous mode and
non-autonomous mode, CPPC firmware will decide frequency at 1ms timescale
based on the workload utilization.

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