Revert "ACPI: processor: Remove unused empty stubs of some functions"

Revert commit 5020d05 ("ACPI: processor: Remove unused empty stubs
of some functions") because it depends on a problematic one.

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

Author: rafaeljw

include/acpi/processor.h

@@ -425,6 +425,26 @@ int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
 int acpi_processor_hotplug(struct acpi_processor *pr);
 void acpi_processor_register_idle_driver(void);
 void acpi_processor_unregister_idle_driver(void);
+#else
+static inline int acpi_processor_power_init(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_power_exit(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_hotplug(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_ACPI_PROCESSOR_IDLE */
 
 /* in processor_thermal.c */