dm: core: Add a function to bind child devices

We currently use dm_scan_fdt_node() to bind devices. It is an internal
function and it requires the caller to know whether we are pre- or post-
relocation.

This requirement has become quite common in drivers, so the current function
is not ideal.

Add a new function with fewer arguments, that does not require internal
headers. This can be used directly as a post_bind() method if needed.

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

include/dm/device.h

@@ -612,6 +612,22 @@ static inline bool device_is_on_pci_bus(struct udevice *dev)
 #define device_foreach_child_safe(pos, next, parent)	\
 	list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
 
+/**
+ * dm_scan_fdt_dev() - Bind child device in a the device tree
+ *
+ * This handles device which have sub-nodes in the device tree. It scans all
+ * sub-nodes and binds drivers for each node where a driver can be found.
+ *
+ * If this is called prior to relocation, only pre-relocation devices will be
+ * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
+ * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
+ * be bound.
+ *
+ * @dev:	Device to scan
+ * @return 0 if OK, -ve on error
+ */
+int dm_scan_fdt_dev(struct udevice *dev);
+
 /* device resource management */
 typedef void (*dr_release_t)(struct udevice *dev, void *res);
 typedef int (*dr_match_t)(struct udevice *dev, void *res, void *match_data);