populate_sdk_ext: Allow generation of meta-extsdk-toolchain even for minimal SDKs
If you build a minimal eSDK currently, you don't build meta-extesdk-toolchain
even if you will have built most of its dependencies. This means when you try
and install a toolchain into the eSDK, it fails, breaking our automated testing
of the eSDK.
Therefore add the dependency unconditionally even when a minimal eSDK is being
built and allow the automated testing to work.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
