RISC-V: Fixed wrong imply result for zce when -march=rv32id_zce

The entry of "zce imply zcf" needs check_implicit_for_zcf, so it needs to be
placed after the entries of "whatever imply f".  Otherwise the implicit zcf
may be missed.  Also merge the march-implu-zce* testcases into imply testcases.
6 files changed