The PCIex4_ECP2M35_PCIex4Demo_1_0.bit bitstream supports both ES and 
Production version of the ECP2M35 silicon.

For ES silicon, set the dip_switches as follow for booting:
SW5  DDDD
SW6  DDDU


For Production silicon, set the dip_switches as follow for booting:
SW5  DDDD
SW6  DDDD

