ACPI: move acpi_no_s4_hw_signature() declaration into #ifdef CONFIG_HIBERNATION

acpi_no_s4_hw_signature is defined in #ifdef CONFIG_HIBERNATION block,
but the current code put the declaration in #ifdef CONFIG_PM_SLEEP block.

I happened to meet this issue when I turned off PM_SLEEP config manually:
arch/x86/kernel/acpi/sleep.c:100:4: error: implicit declaration of function ‘acpi_no_s4_hw_signature’ [-Werror=implicit-function-declaration]
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/linux/acpi.h

@@ -257,8 +257,11 @@ int acpi_check_region(resource_size_t start, resource_size_t n,
 
 int acpi_resources_are_enforced(void);
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_HIBERNATION
 void __init acpi_no_s4_hw_signature(void);
+#endif
+
+#ifdef CONFIG_PM_SLEEP
 void __init acpi_old_suspend_ordering(void);
 void __init acpi_nvs_nosave(void);
 void __init acpi_nvs_nosave_s3(void);