platform/x86: hfi: Add power management callback

Introduce power management callbacks for the `amd_hfi` driver. Specifically,
add the `suspend` and `resume` callbacks to handle the necessary operations
during system low power states and wake-up.

Signed-off-by: Perry Yuan <[e-mail]>
Co-developed-by: Mario Limonciello <[e-mail]>
Signed-off-by: Mario Limonciello <[e-mail]>
Signed-off-by: Borislav Petkov (AMD) <[e-mail]>
Reviewed-by: Gautham R. Shenoy <[e-mail]>
Acked-by: Ilpo Järvinen <[e-mail]>
Link: https://lore.kernel.org/[e-mail]

drivers/platform/x86/amd/hfi/hfi.c

···
 	return ret;
 }
 
+static int amd_hfi_pm_resume(struct device *dev)
+{
+	int ret, cpu;
+
+	for_each_online_cpu(cpu) {
+		ret = amd_hfi_set_state(cpu, true);
+		if (ret < 0) {
+			dev_err(dev, "failed to enable workload class config: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int amd_hfi_pm_suspend(struct device *dev)
+{
+	int ret, cpu;
+
+	for_each_online_cpu(cpu) {
+		ret = amd_hfi_set_state(cpu, false);
+		if (ret < 0) {
+			dev_err(dev, "failed to disable workload class config: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(amd_hfi_pm_ops, amd_hfi_pm_suspend, amd_hfi_pm_resume);
+
 static const struct acpi_device_id amd_hfi_platform_match[] = {
 	{"AMDI0104", 0},
 	{ }
···
 	.driver = {
 		.name = AMD_HFI_DRIVER,
 		.owner = THIS_MODULE,
+		.pm = &amd_hfi_pm_ops,
 		.acpi_match_table = ACPI_PTR(amd_hfi_platform_match),
 	},
 	.probe = amd_hfi_probe,