ACPI: PM: s2idle: Move x86-specific code to the x86 directory

Some code in drivers/acpi/sleep.c (which is regarded as a generic
file) related to suspend-to-idle support has grown direct dependencies
on x86, but in fact it has been specific to x86 (which is the only
user of it) anyway for a long time.

For this reason, move that code to a separate file under acpi/x86/
and make it build and run as before under the right conditions.

While at it, rename a vendor checking function in that code and
consistently use acpi_handle_debug() for printing debug-related
information in it.

No expected functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/Makefile

@@ -54,6 +54,7 @@ acpi-y				+= property.o
 acpi-$(CONFIG_X86)		+= acpi_cmos_rtc.o
 acpi-$(CONFIG_X86)		+= x86/apple.o
 acpi-$(CONFIG_X86)		+= x86/utils.o
+acpi-$(CONFIG_X86)		+= x86/s2idle.o
 acpi-$(CONFIG_DEBUG_FS)		+= debugfs.o
 acpi-y				+= acpi_lpat.o
 acpi-$(CONFIG_ACPI_LPIT)	+= acpi_lpit.o

drivers/acpi/sleep.h

@@ -15,3 +15,19 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
 	return acpi_set_firmware_waking_vector(
 				(acpi_physical_address)wakeup_address, 0);
 }
+
+extern int acpi_s2idle_begin(void);
+extern int acpi_s2idle_prepare(void);
+extern int acpi_s2idle_prepare_late(void);
+extern bool acpi_s2idle_wake(void);
+extern void acpi_s2idle_restore_early(void);
+extern void acpi_s2idle_restore(void);
+extern void acpi_s2idle_end(void);
+
+extern void acpi_s2idle_setup(void);
+
+#ifdef CONFIG_ACPI_SLEEP
+extern bool acpi_sleep_default_s3;
+#else
+#define acpi_sleep_default_s3	(1)
+#endif