Revert "x86, AMD: Fix APIC timer erratum 400 affecting K8 Rev.A-E processors"

This reverts commit e20a2d20, as it crashes
certain boxes with specific AMD CPU models.

Moving the lower endpoint of the Erratum 400 check to accomodate
earlier K8 revisions (A-E) opens a can of worms which is simply
not worth to fix properly by tweaking the errata checking
framework:

* missing IntPenging MSR on revisions < CG cause #GP:

http://marc.info/?l=linux-kernel&m=130541471818831

* makes earlier revisions use the LAPIC timer instead of the C1E
idle routine which switches to HPET, thus not waking up in
deeper C-states:

http://lkml.org/lkml/2011/4/24/20



Therefore, leave the original boundary starting with K8-revF.

Signed-off-by: Ingo Molnar <mingo@elte.hu>