Increase timeout for clang-sparc64-linux to 1800 seconds (#513)

The builds for clang-sparc64-linux currently fail with a timeout during
the linking stage, so lets increase the timeout to 1800 seconds which is
the timeout also used on the builder clang-solaris11-sparcv9.

Author: glaubitz

buildbot/osuosl/master/config/builders.py

@@ -818,6 +818,7 @@
     'builddir': 'clang-sparc64-linux',
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
+                    timeout=1800,
                     runTestSuite=True,
                     checkout_clang_tools_extra=False,
                     checkout_compiler_rt=False,