Constify option parameter for better compiler analysis

runtime/parsec/codelets/codelet_zlag2c.c

runtime/parsec/codelets/codelet_zlange.c

runtime/parsec/codelets/codelet_zlanhe.c

runtime/parsec/codelets/codelet_zlansy.c

runtime/parsec/codelets/codelet_zlantr.c

runtime/parsec/codelets/codelet_zlaset.c

runtime/parsec/codelets/codelet_zlaset2.c

runtime/parsec/codelets/codelet_zlauum.c

runtime/parsec/codelets/codelet_zpamm.c

runtime/parsec/codelets/codelet_zplghe.c

runtime/parsec/codelets/codelet_zplgsy.c

runtime/parsec/codelets/codelet_zplrnt.c

runtime/parsec/codelets/codelet_zplssq.c

runtime/parsec/codelets/codelet_zpotrf.c

runtime/parsec/codelets/codelet_zssssm.c

runtime/parsec/codelets/codelet_zsymm.c

runtime/parsec/codelets/codelet_zsyr2k.c

runtime/parsec/codelets/codelet_zsyrk.c

runtime/parsec/codelets/codelet_zsyssq.c

runtime/parsec/codelets/codelet_zsytrf_nopiv.c