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="Harold Grovesteen"

reporter_url="http://sourceware.org/ml/crossgcc/2009-11/msg00052.html"

reporter_comment=""