acpi sleep: move sleep support into own subdirectory.

drivers/acpi/Makefile

@@ -42,7 +42,7 @@ obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
 obj-$(CONFIG_ACPI_THERMAL)	+= thermal.o
 obj-$(CONFIG_ACPI_SYSTEM)	+= system.o event.o
 obj-$(CONFIG_ACPI_DEBUG)	+= debug.o
-obj-$(CONFIG_ACPI_SLEEP)	+= sleep.o
+obj-$(CONFIG_ACPI_SLEEP)	+= sleep/
 obj-$(CONFIG_ACPI_NUMA)		+= numa.o
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o
 obj-$(CONFIG_ACPI_BUS)		+= scan.o 

drivers/acpi/sleep/Makefile

+obj-y	:= main.o
+
+EXTRA_CFLAGS += $(ACPI_CFLAGS)