acpi-cpufreq: Honor _PSD table setting on new AMD CPUs

commit 5368512 upstream.

acpi-cpufreq has a old quirk that overrides the _PSD table supplied by
BIOS on AMD CPUs. However the _PSD table of new AMD CPUs (Family 19h+)
now accurately reports the P-state dependency of CPU cores. Hence this
quirk needs to be fixed in order to support new CPUs' frequency control.

Fixes: acd3162 ("acpi-cpufreq: Add quirk to disable _PSD usage on all AMD CPUs")
Signed-off-by: Wei Huang <wei.huang2@amd.com>
[ rjw: Subject edit ]
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/cpufreq/acpi-cpufreq.c

@@ -691,7 +691,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
 	}
 
-	if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
+	if (check_amd_hwpstate_cpu(cpu) && boot_cpu_data.x86 < 0x19 &&
+	    !acpi_pstate_strict) {
 		cpumask_clear(policy->cpus);
 		cpumask_set_cpu(cpu, policy->cpus);
 		cpumask_copy(data->freqdomain_cpus,