amd64_edac: Simplify decoding path

Use the struct mce directly instead of copying from it into a custom
struct err_regs.

No functionality change.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

diff --cc drivers/edac/amd64_edac.c
Simple merge

diff --cc drivers/edac/amd64_edac.h
Simple merge

diff --cc drivers/edac/mce_amd.h
Simple merge