avoid dereferencing NULL pointer in lib_arm/armlinux.c

* Patch by Stephen Williams, 15 Mar 2004:
  Fix CONFIG_SERIAL_SOFTWARE_FIFO documentation

* Patch by Tolunay Orkun, 15 Mar 2004:
  Initialize bi_opbfreq to real OPB frequency via get_OPB_freq()

* Patch by Travis Sawyer, 15 Mar 2004:
  Update CREDITS & MAINTAINERS files for PPC440GX & Ocotea port

add support for USB-based console
(enable with "setenv stdout usbtty; setenv stdin usbtty")

  Add support for S3C44B0 processor and DAVE B2 board

* Patch by Steven Scholz, 20 Feb 2004:
  - Add support for MII commands on AT91RM9200 boards
  - some cleanup in AT91RM9200 ethernet code

ARM memory layout fixes: the abort-stack is now set up in the
correct RAM area, and the BSS is zeroed out as it should be.

Furthermore, the magic variables 'armboot_end' and 'armboot_end_data'
of the linker scripts are replaced by '__bss_start' and '_end',
resp., which is a further step to eliminate unnecessary differences
between the implementation of the CPU architectures.

  made CONFIG_SILENT_CONSOLE usable on all architectures

* Disable date command on TQM866M - there is no RTC on MPC866

  before we can access it; add delay in case we are faster (with no
  CF card inserted)

* Cleanup of some init functions

* Make sure SCC Ethernet is always stopped by the time we boot Linux
  to avoid Linux crashes by early packets coming in.

* Accelerate flash accesses on LWMON board by using buffered writes

  - add support for the PATI board (MPC555)
  - add SPI support for the MPC5xx

* Patch by Anders Larsen, 08 Dec 2003:
  add configuration options CONFIG_SERIAL_TAG and CONFIG_REVISION_TAG
  to pass ATAG_SERIAL and ATAG_REVISION, resp., to the ARM target;
  cleanup some redundand #defines

  - board/mpl/common/common_util.c
    * implement support for BZIP2 compressed images
    * various cleanups (printf -> puts, ...)
  - board/mpl/common/flash.c
    * report correct errors to upper layers
    * check the erase fail and VPP low bits in status reg
  - board/mpl/vcma9/cmd_vcma9.c
  - board/mpl/vcma9/flash.c
    * various cleanups (printf -> puts, ...)
  - common/cmd_usb.c
    * fix typo in comment
  - cpu/arm920t/usb_ohci.c
    * support for S3C2410 is missing in #if line
  - drivers/cs8900.c
    * reinit some registers in case of error (cable missing, ...)
  - fs/fat/fat.c
    * support for USB/MMC devices is missing in #if line
  - include/configs/MIP405.h
  - include/configs/PIP405.h
    * enable BZIP2 support
    * enlarge malloc space to 1MiB because of BZIP2 support
  - include/configs/VCMA9.h
    * enable BZIP2 support
    * enlarge malloc space to 1MiB because of BZIP2 support
    * enable USB support
  - lib_arm/armlinux.c
    * change calling convention of ARM Linux kernel as
      described on http://www.arm.linux.org.uk/developer/booting.php

* Patch by Thomas Lange, 14 Nov 2003:
  Split dbau1x00 into dbau1000, dbau1100 and dbau1500 configs to
  support all these AMD boards.

* Patch by Thomas Lange, 14 Nov 2003:
  Workaround for mips au1x00 physical memory accesses (the au1x00
  uses a 36 bit bus internally and cannot access physical memory
  directly. Use the uncached SDRAM address instead of the physical
  one.)

  add Realtek 8019 ethernet driver

* Patch by Yuli Barcohen, 13 Nov 2003:
  MPC826xADS/PQ2FADS  cleanup

* Patch by Anders Larsen, 12 Nov 2003:
  Update README to mark the PORTIO commands non-standard

  update for for Atmel AT91RM9200DK development kit:
  - support for environment variables in DataFlash
  - Atmel DataFlash AT45DB1282 support

* Patch by Jeff Carr, 11 Nov 2003:
  add support for new version of 8270 processors

* Patches by George G. Davis, 05 Nov 2003:
  - only pass the ARM linux initrd tag to the kernel when an initrd
    is actually present
  - update omap1510inn configuration file