Update gpio.py to support generic gpio devices (#857)
Update gpio.py to support generic gpio devices (#857)


cathalmccabe/PYNQ,yunqu/PYNQ,Xilinx/PYNQ,Xilinx/PYNQ,Xilinx/PYNQ,cathalmccabe/PYNQ,schelleg/PYNQ,yunqu/PYNQ,yunqu/PYNQ,schelleg/PYNQ,Xilinx/PYNQ,schelleg/PYNQ,yunqu/PYNQ,cathalmccabe/PYNQ,cathalmccabe/PYNQ,schelleg/PYNQ,yunqu/PYNQ,Xilinx/PYNQ,schelleg/PYNQ,cathalmccabe/PYNQ,cathalmccabe/PYNQ