sb/i82801ix: Use macros instead of hard-coded IDs

sb/i82801ix: Use macros instead of hard-coded IDs

This patch replaces hard-coded PCI IDs with macros
from pci_ids.h and cleans up some code.

Change-Id: Ie6ea72ac49eb015ef5cbaa98ed2b3400072000b5
Signed-off-by: Felix Singer <felix.singer@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36705
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>