documentation: Remove refs to seemingly native toolchains issue

Remove references to the seemingly native toolchains do not build
issue as it seems to be fixed.

Signed-off-by: Richard Strand <richard.strand@icomera.com>

 reporter_name="Alexander BIGGA"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-06/msg00031.html"

 reporter_comment=""