[PowerPC] Use an unversioned FreeBSD triple in pr47373.ll (#233652)

pr47373.ll was added in 27714075848e with powerpc64-unknown-freebsd13.0,
but at the time llc defaulted to ELFv1 for all big-endian ppc64
triples, so the generated checks were ELFv1 even though FreeBSD 13
uses ELFv2. 4b09cb2b16eb made llc select ELFv2 for FreeBSD 13+ and
worked around the resulting failure by changing the triple to
freebsd12.0.

Use powerpc64-unknown-freebsd and regenerate the checks. The test
covers vector FDIV lowering without VSX, which is unaffected by the
ABI.

GitOrigin-RevId: fa12d94d6041fe984e42f4334d42658cc73bd92f