Advertise the register spacing used by the BMC as set by the Kconfig. Tested on OCP Monolake. Change-Id: Ib926d30f6a0e78fbf613a6f71f765c5f51eee77d Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/35152 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>