sbxxx: Handle active IMCs in AMD chipsets

Detect and temporarily disable the IMC while accessing the flash.
Disable writes on default, but allow the user to enforce it.

Corresponding to flashrom svn r1704.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: David Hendricks <dhendrix@google.com>
5 files changed