[PowerPC] Disable oggenc test case in testsuite

This test has problems running on powerpc starting with r295538 and should
be restored when the issue is corrected.  This specific revision disables it
when the tests are set up via cmake.

ref:  r296630



git-svn-id: https://llvm.org/svn/llvm-project/test-suite/trunk@297469 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed