8 MB D-TLB's break 8xx without CONFIG_8xx_CPU6

[Kalle Pokki]

Hi,

Can you please review the 8 MB D-TLB change introduced by
8f069b1a90bd97bf6d59a02ecabf0173d9175609 again? Even though I also
have the two patches that fix this commit, I always get an oops when
the init process is supposed to start. The only way to run the board
is to have CONFIG_8xx_CPU6 enabled, and I'd rather avoid that since I
only have 860's with the D.4 mask that are not supposed to be affected
by CPU6.