This version adds support for NAND flash block testing,
and support for serial consoles on SMC1, SMC2, SCC1,
SCC2, SCC3, and SCC4. The CPU speed calculation
code has been fixed - it used to depend on a value
stored in DPRAM by PPCBoot. Now the value is
calculated when the diagnostics start up is used instead
(can be overridden by setting CPU_CLOCK_RATE in
config.h). This should hopefully allow the diagnostics to
start up properly when run from a hardware debugger
(such as the BDI 2000 from Abatron).
