zeroized mem read ports

[ekarabu]

@Nitsirks needs to review this change

The MLDSA RTL correctly enters the zeroization flow, but the last read data remains on the read ports after zeroization completes. This occurs because the read data port retains the last-read value just before zeroization.

To prevent this, I enforce a read operation at address zero during zeroization. As a result, three clock cycles after receiving the zeroization command, the read port outputs data from address zero, which has already been cleared by the memory zeroization routine.

This ensures that no stale data remains on the read ports post-zeroization. This also ensures that read data port is zeroized at the 3rd clock cycle after receiving the zeroization command.