cpufreq: intel_pstate: Use load-based P-state selection more widely

Extend the set of systems for which intel_pstate will use the
"powersave" P-state selection algorithm based on CPU load in the
active mode by systems with ACPI preferred profile set to "tablet",
"appliance PC", "desktop", or "workstation" (ie. everything with a
specified preferred profile that is not a "server").

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>