dm: pci: Allow PCI bus numbering aliases

Commit 9cc36a2b 'dm: core: Add a flag to control sequence numbering' changed
the default uclass behaviour to not support bus numbering. This is incorrect
for PCI and that commit should have enabled the flag for PCI.

Enable it so that PCI buses can be found and the 'pci' command works again.
Also add a test for this.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/pci/pci-uclass.c

@@ -596,6 +596,7 @@ int pci_bridge_write_config(struct udevice *bus, pci_dev_t devfn, uint offset,
 UCLASS_DRIVER(pci) = {
 	.id		= UCLASS_PCI,
 	.name		= "pci",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
 	.post_bind	= pci_uclass_post_bind,
 	.pre_probe	= pci_uclass_pre_probe,
 	.post_probe	= pci_uclass_post_probe,

test/dm/pci.c

@@ -21,6 +21,17 @@ static int dm_test_pci_base(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_pci_base, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
 
+/* Test that sandbox PCI bus numbering works correctly */
+static int dm_test_pci_busnum(struct unit_test_state *uts)
+{
+	struct udevice *bus;
+
+	ut_assertok(uclass_get_device_by_seq(UCLASS_PCI, 0, &bus));
+
+	return 0;
+}
+DM_TEST(dm_test_pci_busnum, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
 /* Test that we can use the swapcase device correctly */
 static int dm_test_pci_swapcase(struct unit_test_state *uts)
 {