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