Remove clock_en_i port from toplevel
Remove clock_en_i port from toplevel

The clock_en_i signal is unused within the module, as the clock_en
signal is generated from internal core state.

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