PCI/sysfs: Use default_groups in kobj_type for slot attrs

There are currently two ways to create a set of sysfs files for a
kobj_type: through the default_attrs field, and the default_groups field.
Move the PCI slot code to use the default_groups field which has been the
preferred way since aa30f47c ("kobject: Add support for default
attribute groups to kobj_type") so that we can soon get rid of the obsolete
default_attrs field.

Link: https://lore.kernel.org/r/20211228135722.381023-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/slot.c

@@ -96,11 +96,12 @@ static struct attribute *pci_slot_default_attrs[] = {
 	&pci_slot_attr_cur_speed.attr,
 	NULL,
 };
+ATTRIBUTE_GROUPS(pci_slot_default);
 
 static struct kobj_type pci_slot_ktype = {
 	.sysfs_ops = &pci_slot_sysfs_ops,
 	.release = &pci_slot_release,
-	.default_attrs = pci_slot_default_attrs,
+	.default_groups = pci_slot_default_groups,
 };
 
 static char *make_slot_name(const char *name)