Recognise "i686" as an x86 CPU.

Building under Ubuntu x86 fails with "Unknown processor:i686".

This adds i686 to CMakeLists.txt, fixing the build.

Change-Id: Ic1c7ce452c019b8a2a875d64a707f640d86c7e31

CMakeLists.txt

@@ -27,6 +27,8 @@ elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86")
 	set(ARCH "x86")
 elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "i386")
 	set(ARCH "x86")
+elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "i686")
+	set(ARCH "x86")
 elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "arm")
 	set(ARCH "arm")
 else()