ACPI: AC: Add sysfs interface

Refer to Documentation/power_supply_class.txt for interface description.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ba6a61f..a858bc5 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -88,7 +88,7 @@
 
 config ACPI_AC
 	tristate "AC Adapter"
-	depends on X86
+	depends on X86 && POWER_SUPPLY
 	default y
 	help
 	  This driver adds support for the AC Adapter object, which indicates