pc-bios: petalogix-s3adsp1800.dtb: Use 'xlnx, xps-ethernetlite-2.00.a' instead of 'xlnx, xps-ethernetlite-2.00.b'
For Linux upstream kernel (e.g. 3.17-rc7), the related compatible string
'xlnx,xps-ethernetlite-2.00.a' is supported, but 'b' is not supported,
so change qemu dtb file to match kernel driver.
The related operation for qemu (after this patch):
yum install libvirt
yum install tunctl
tunctl -b
ip link set tap0 up
brctl addif virbr0 tap0