ACPICA: Cleanup asmlinkage for ACPICA APIs.

Add an asmlinkage wrapper around acpi_enter_sleep_state() to prevent
an empty stub from being called by assmebly code for ACPI_REDUCED_HARDWARE
set.

As arch/x86/kernel/acpi/wakeup_xx.S is only compiled when CONFIG_ACPI=y
and there are no users of ACPI_HARDWARE_REDUCED, currently this is in
fact not a real issue, but a cleanup to reduce source code differences
between Linux and ACPICA upstream.

[rjw: Changelog]
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c
index 4895fca..15dddc1 100644
--- a/drivers/acpi/acpica/hwxfsleep.c
+++ b/drivers/acpi/acpica/hwxfsleep.c
@@ -167,7 +167,7 @@
  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
  *
  ******************************************************************************/
-acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
+acpi_status acpi_enter_sleep_state_s4bios(void)
 {
 	u32 in_value;
 	acpi_status status;
@@ -361,7 +361,7 @@
  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
  *
  ******************************************************************************/
-acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
+acpi_status acpi_enter_sleep_state(u8 sleep_state)
 {
 	acpi_status status;