soc/intel/apollolake: Update SPI memory mapping constraints

MMIO region of 256 KiB under 4 GiB is not decoded by SPI controller
by hardware design. Current code incorrectly specifies size of that
region to be 128 KiB. This change corrects the value to 256 KiB.

Change-Id: Idcc67eb3565b800d835e75c0b765dd49d1656938
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/14979
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
1 file changed