Patches by Stephan Linz, 11 Dec 2003:

- more documentation for NIOS port
- new struct nios_pio_t, struct nios_spi_t
- Reconfiguration for NIOS Development Kit DK1C20:
  o move board related code from board/dk1c20
    to board/altera/dk1c20
  o create a new common source path board/altera/common
    and move generic flash access stuff into it
  o change/expand configuration file DK1C20.h
- Add support for NIOS Development Kit DK1S10
- Add status LED support for NIOS systems
- Add dual 7-segment LED support for Altera NIOS DevKits