dm: Use dm_scan_fdt_dev() directly where possible

Quite a few places have a bind() method which just calls dm_scan_fdt_dev().
We may as well call dm_scan_fdt_dev() directly. Update the code to do this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/spmi/spmi-uclass.c b/drivers/spmi/spmi-uclass.c
index 9fa330b..6edece2 100644
--- a/drivers/spmi/spmi-uclass.c
+++ b/drivers/spmi/spmi-uclass.c
@@ -35,13 +35,8 @@
 	return ops->write(dev, usid, pid, reg, value);
 }
 
-static int spmi_post_bind(struct udevice *dev)
-{
-	return dm_scan_fdt_dev(dev);
-}
-
 UCLASS_DRIVER(spmi) = {
 	.id		= UCLASS_SPMI,
 	.name		= "spmi",
-	.post_bind	= spmi_post_bind,
+	.post_bind	= dm_scan_fdt_dev,
 };