added UART and I2C pins to vc709.json
added UART and I2C pins to vc709.json

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