apic, amd: Make firmware bug messages more meaningful

This improves error messages in case the BIOS was setting up
wrong LVT offsets.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1288015419-29543-6-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>