Add support for indexed IO for ec communication, Indexed I/O allows
memory access using a single I/O port base address usually called an
index register and another port address called a data register.
BUG=b:379224648
TEST= able to build nissa/trulo.
Change-Id: I6c1aab3fc914eb5af2736a8ea3adf447040905e0
Signed-off-by: Jayvik Desai <jayvik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85449
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Caveh Jalali <caveh@chromium.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>
1e90bbadfa