clpf_test: mark TestSpeed disabled
clpf_test: mark TestSpeed disabled

performance characteristics in test environments vary, speed tests
should be for local performance testing. these can still be run with:
--gtest_filter=*TestSpeed* --gtest_also_run_disabled_tests

Change-Id: I96a05fe72336b7654ae832d3d2114dacc8203aa5

smarter/aom,GrokImageCompression/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,smarter/aom,GrokImageCompression/aom,smarter/aom,GrokImageCompression/aom