changed ref_clk to 50MHz
changed ref_clk to 50MHz

hanw/connectal,csail-csg/connectal,chenm001/connectal,hanw/connectal,cambridgehackers/connectal,cambridgehackers/connectal,chenm001/connectal,cambridgehackers/connectal,hanw/connectal,cambridgehackers/connectal,csail-csg/connectal,csail-csg/connectal,chenm001/connectal,csail-csg/connectal,chenm001/connectal,chenm001/connectal,csail-csg/connectal,cambridgehackers/connectal,hanw/connectal,hanw/connectal