octeon1: suppress a couple of warnings under clang

These appear in octeon-sdk -- there are new releases, but they don't seem to
address the running issues in octeon-sdk. GCC4.2 is more than happy, but
clang is much less-so and most of them are fairly innocuous and perhaps a
by-product of their style guide, which may make some of the changes harder
to upstream (if this is even possible anymore).