fix welcome leds for z1 and z2
fix welcome leds for z1 and z2

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