[dv,core_ibex] Fix order of 'm' and 'c' in ISA string
[dv,core_ibex] Fix order of 'm' and 'c' in ISA string

Recent versions of Spike allow rv32imc but not rv32icm.

lowRISC/ibex,lowRISC/ibex,lowRISC/ibex,lowRISC/ibex,AmbiML/ibex,AmbiML/ibex,AmbiML/ibex,AmbiML/ibex