dmaengine: ioatdma: use default_groups in kobj_type

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the ioatdma sysfs code to use default_groups field which has
been the preferred way since aa30f47cf666 ("kobject: Add support for
default attribute groups to kobj_type") so that we can soon get rid of
the obsolete default_attrs field.

Cc: Vinod Koul <[e-mail]>
Cc: [e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>
Acked-by: Dave Jiang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/ioat/sysfs.c

···
 	&intr_coalesce_attr.attr,
 	NULL,
 };
+ATTRIBUTE_GROUPS(ioat);
 
 struct kobj_type ioat_ktype = {
 	.sysfs_ops = &ioat_sysfs_ops,
-	.default_attrs = ioat_attrs,
+	.default_groups = ioat_groups,
 };