base.bbclass: Fix multilib PREFERRED_VERSION handling

Now that gcc-cross, gcc-crosssdk and others have expanded variables in
their names, the code that previous just applied to cross-canadian needs
expanding to cover the other cases. Improve the conditional and also
fix a bug where the multilib prefix wasn't being added into the generated
versions.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
python3/gcc/autoconf: Fix Upstream-Status in some patches I authored

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>