cpufreq: amd-pstate: Add fast switch function for AMD P-State

cpufreq: amd-pstate: Add fast switch function for AMD P-State

BugLink: https://bugs.launchpad.net/bugs/1956509
Introduce the fast switch function for AMD P-State on the AMD processors
which support the full MSR register control. It's able to decrease the
latency on interrupt context.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 1d215f0319c20662b701692a2fafc7b3b8a58ae1)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>