Add support for the Xilinx ML300 platform

* Patch by Stephan Linz, 17 Feb 2004:
  Fix watchdog support for NIOS

* Patch by Josh Fryman, 16 Feb 2004:
  Fix byte-swapping for cfi_flash.c for different bus widths

* Patch by Jon Diekema, 14 Jeb 2004:
  Remove duplicate "FPGA Support" notes from the README file