[PowerPC][NFC] Add more check directives in only cxx_fast_tlscc lit test.

Use utils/update_llc_test_checks.py to add full CHECK directives to the
test for cxx_fast_tls calling convention. The calling convention is
arguably dead on PowerPC since dropping Darwin subtarget support in the PowerPC
backend. This test change helps show the atrocious code generation for
this lit test which was hidden by having few CHECK directives.