[coreboot] [PATCH][again] 440BX raminit cleanup

[Keith Hui]

A number of cleanups for 440BX raminit code.

Resolves a number of TODOs items within, and clarified a number of other TODOs.
Change register_values[] from long to u8 (byte). For what we are doing
this is sufficient and makes it only 1/4 the size.
Remove a hard-coding of SDRAMC register that is redundant and now
incorrect, now that SDRAMC is conditioned on SDRAMPWR_4DIMM Kconfig
and set through register_values[].
RPS registers are now set in runtime code; remove it from
register_values[] table.
Bring DUMPNORTH() back. The code it refers to is still there.
Move #define of NB up so the DUMPNORTH() macro can use it.

Signed-off-by: Keith Hui