Use i686-linux-android-4.6 for x86 build

Change-Id: Ibbb0a899f147013503d6830bb93050c5ae588539
Author: "H.J. Lu" <hongjiu.lu@intel.com>
diff --git a/envsetup.sh b/envsetup.sh
index 609e1af..6ad4600 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -117,7 +117,7 @@
     # The gcc toolchain does not exists for windows/cygwin. In this case, do not reference it.
     export ANDROID_EABI_TOOLCHAIN=
     case $(get_build_var TARGET_ARCH) in
-        x86) toolchaindir=x86/i686-android-linux-4.4.3/bin
+        x86) toolchaindir=x86/i686-linux-android-4.6/bin
             ;;
         arm|*) toolchaindir=arm/arm-linux-androideabi-4.6/bin
             ;;