soc/intel/tigerlake: Invoke PCIe root port swapping

PCIe bus:function specifiers need to be coalesced the same way
functions are coalesced during bus enumeration. Invoke PCIe root port
devicetree update to swap the enabled root port devices with the
disabled devices.

At this point, the TGL pci_devs.h only describes the PCH-LP, so only
the PCH-LP root ports are listed in this patch. We'll need to add
additional PCIe root ports when PCH-H support is added.

BUG=b:162106164
TEST=Ensure that the PCIe device 1c.7 corresponding to Root port 8 is
swapped with the PCIe device 1c.0 corresponding to Root port 1.

Change-Id: I9230de8b1818f3f2115dab923841fd0e7778be62
Signed-off-by: Caveh Jalali <caveh@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43850
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/soc/intel/tigerlake/chip.c

@@ -8,6 +8,7 @@
 #include <intelblocks/acpi.h>
 #include <intelblocks/cfg.h>
 #include <intelblocks/itss.h>
+#include <intelblocks/pcie_rp.h>
 #include <intelblocks/xdci.h>
 #include <romstage_handoff.h>
 #include <soc/intel/common/vbt.h>
@@ -16,6 +17,12 @@
 #include <soc/ramstage.h>
 #include <soc/soc_chip.h>
 
+static const struct pcie_rp_group pch_lp_rp_groups[] = {
+	{ .slot = PCH_DEV_SLOT_PCIE,	.count = 8 },
+	{ .slot = PCH_DEV_SLOT_PCIE_1,	.count = 4 },
+	{ 0 }
+};
+
 #if CONFIG(HAVE_ACPI_TABLES)
 const char *soc_acpi_name(const struct device *dev)
 {
@@ -140,6 +147,9 @@ void soc_init_pre_device(void *chip_info)
 	itss_restore_irq_polarities(GPIO_IRQ_START, GPIO_IRQ_END);
 
 	soc_fill_gpio_pm_configuration();
+
+	/* Swap enabled PCI ports in device tree if needed. */
+	pcie_rp_update_devicetree(pch_lp_rp_groups);
 }
 
 static struct device_operations pci_domain_ops = {