POWER10 hardware implements a degenerate transactional memory facility
in POWER8/9 PCR compatibility modes to permit migration from older
CPUs, but POWER10 / ISA v3.1 mode does not support it so the CPU model
should not support it.
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>