drivers: net: ethernet: xilinx: xilinx_emaclite: revert the original commit "1db3ddff"

Microblaze is a fpga soft core, it can be customized easily, which may
cause many various hardware version strings.

So the original fix patch based on hard-coded compatible version strings
is not a good idea (although it is correct for current issue). For it,
there will be a new solving way soon (which based on the device tree).

The original issue is related with qemu, so can only change the hardware
version string in qemu for it, then keep the original driver no touch (
qemu is for virtualization which has much easier life than real world).
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>