There are brief notes about how to enable Thumb-2 kernel building here:

https://wiki.linaro.org/Resources/HowTo/KernelDeploy#From_a_generic_base

Currently, omap and vexpress are known to work in this configuration, and mx51evk seems to have basic support. Other platforms might not work at all.

If people can get into the habit of testing both ARM and Thumb-2 kernel configurations when testing the linaro kernel tree, that would be great!

Cheers ---Dave