soc/intel/*: Use SSDT to pass A4GB and A4GS

soc/intel/*: Use SSDT to pass A4GB and A4GS

GNVS is more fragile as you need to keep struct elements in sync with
ASL code.

Change-Id: I2cd5e6b56e4a0dbbb11f4a0ac97e8f84d53b90ec
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64216
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>