[coreboot] [patch] i82810 WIP - fix for the BUFF_SC

[Elia Yehuda]

this patch calculates BUFF_SC according to set of rules guessed out of
some various results i came up with different DIMM setups.

looking into this patch reveals it is just begging for optimization, so role
up
your sleeves, kick out those old optimization shoes, and see how you handle
this better 8-) (uwe suggested using a table, and no argue there...)

Signed-off-by: Elia Yehuda