systemtap: update to 3.0

Remove docproc-build-fix.patch, as the build problem it's fixing
now happens only if building html docs is explicitly enabled
(which we do not do).

Signed-off-by: Alexander Kanavin <alexander.kanavin@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>