inteltool: Add support for dumping AMB registers

inteltool: Add support for dumping AMB registers

Change-Id: I98615725afdb315caa67b2226224e3eb2a0e4393
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-on: http://review.coreboot.org/525
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>