[yocto] Autobuilder Change: Moving meta-toolchain-gmae builds

[Elizabeth Flanagan]

In order to even out some of the build timing, I've moved the meta-toolchain-gmae builds out to:

http://autobuilder02.pokylinux.org/nightly-external-toolchain/

nightly-external was running substantially longer than other builders (30 hours). This should reduce autobuilder build 
time substantially, however, it does mean that meta-toolchain-gmae needs to be picked up from the 02 server.

If you have any questions or issues with this, please let me know.

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Elizabeth Flanagan
Yocto Project
Release Engineer