x86, olpc-xo1-sci: Add GPE handler and ebook switch functionality

The EC in the OLPC XO-1 delivers GPE events to provide various
notifications. Add the basic code for GPE/EC event processing and
enable the ebook switch, which can be used as a wakeup source.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-8-git-send-email-dsd@laptop.org
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 66b7b9d..8888910 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2087,7 +2087,9 @@
 	select MFD_CORE
 	---help---
 	  Add support for SCI-based features of the OLPC XO-1 laptop:
+	   - EC-driven system wakeups
 	   - Power button
+	   - Ebook switch
 
 endif # X86_32