tests: Skip SPARC tests if the required binaries are missing
tests: Skip SPARC tests if the required binaries are missing

The full-system SPARC tests depend on several binaries that aren't
generally available to the wider community. Flag the tests as skipped
instead of failed if these binaries can't be found.

vovojh/gem5,vovojh/gem5,pombredanne/http-repo.gem5.org-gem5-,vovojh/gem5,pombredanne/http-repo.gem5.org-gem5-,vovojh/gem5,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,pombredanne/http-repo.gem5.org-gem5-,vovojh/gem5,vovojh/gem5,vovojh/gem5,pombredanne/http-repo.gem5.org-gem5-