toolchain/build: Enable gold linker as default

- remove the hack to patch binutils and switch to AOSP 2.23

Change-Id: I476ffbb7a4af3e350ff943ee69a82bbe5ed46518
toolchain/build: Generate makefiles for Android

Change-Id: I3eafca8fe646b5bcf3c56624705370d191386bb9
toolchain/build: Force-enable threads and plugins in gold

Change-Id: Icfcd463337bef86f37454a25f81c7507f139dcf3
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
toolchain/build: Disable building --with-tune=cortex-a9

Change-Id: I98369442d495c1268ecc9921cad7fc29140d70b7