Comment 5 for bug 860556

If you are asking about the options, see https://bugs.launchpad.net/linaro-ci/+bug/859473/comments/35
If you are asking about the mechanics of how to do it automatically, you'll simply want to remove the lines for those config options, append
CONFIG_ARM_THUMB=y
CONFIG_THUMB2_KERNEL=y
to the .config that get's generated from running make defconfig (or whatever you happen to run), and then run 'make oldconfig'
I can't recall, but it *might* be possible to enable them by just appending them to the end. I seem to recall that at some point in the past it just used the latest setting in the .config for any given config option.