toolchain-external: update Linaro ARM toolchains

Add Linaro ARM 2013.10 and Linaro ARM 2013.11, and remove Linaro ARM
2013.07 and Linaro ARM 2013.08.

The main change for those versions is the switch to eglibc 2.18.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>