eeepc-laptop: add backlight

Add backlight class support to the eeepc-laptop driver.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 2264127..01b7deb 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -355,6 +355,7 @@
 	tristate "Eee PC Hotkey Driver (EXPERIMENTAL)"
 	depends on X86
 	depends on ACPI
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on EXPERIMENTAL
 	---help---
 	  This driver supports the Fn-Fx keys on Eee PC laptops.