ACPI / sleep: Introduce acpi_os_prepare_extended_sleep() for extended sleep path

Like acpi_os_prepare_sleep(), register a callback for use in systems
like tboot, and xen, which have system specific requirements outside
of ACPICA.  This mirrors the functionality in acpi_os_prepare_sleep(),
called from acpi_hw_sleep()

Signed-off-by: Ben Guthro <benjamin.guthro@citrix.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/hwesleep.c

@@ -43,6 +43,7 @@
  */
 
 #include <acpi/acpi.h>
+#include <linux/acpi.h>
 #include "accommon.h"
 
 #define _COMPONENT          ACPI_HARDWARE
@@ -128,6 +129,14 @@ acpi_status acpi_hw_extended_sleep(u8 sleep_state)
 
 	ACPI_FLUSH_CPU_CACHE();
 
+	status = acpi_os_prepare_extended_sleep(sleep_state,
+						acpi_gbl_sleep_type_a,
+						acpi_gbl_sleep_type_b);
+	if (ACPI_SKIP(status))
+		return_ACPI_STATUS(AE_OK);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
+
 	/*
 	 * Set the SLP_TYP and SLP_EN bits.
 	 *