Lattice encrypted bitstreams #432

…itstreams, by adding key and preamble of encrypted bitstreams to if statements.

…MHZ(1) (i.e. 1MHz) as at 6MHz the download of bitstreams is not stable. With "not stable" we mean that: - when dealing with Certus/Crosslink, most of the times it works - when dealing with CertusPro devices, most of the times it doesn't work We think this is due to the size of the bitstream and the way that the transmission/storing is handled on the receiving side (i.e. the FPGA).