soc/amd/*/root_complex: reserve PCI config IO ports

This makes sure that the resource allocator won't use those ports for
anything else.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ie42260902ee2b383dd5867ac813cae029f706f2d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75556
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
diff --git a/src/soc/amd/picasso/root_complex.c b/src/soc/amd/picasso/root_complex.c
index 5ea8b79..65021a3 100644
--- a/src/soc/amd/picasso/root_complex.c
+++ b/src/soc/amd/picasso/root_complex.c
@@ -115,6 +115,8 @@
 	/* The root complex has no PCI BARs implemented, so there's no need to call
 	   pci_dev_read_resources for it */
 
+	fixed_io_range_reserved(dev, idx++, PCI_IO_CONFIG_INDEX, PCI_IO_CONFIG_PORT_COUNT);
+
 	/* 0x0 - 0x9ffff */
 	ram_resource_kb(dev, idx++, 0, 0xa0000 / KiB);