dm: device: Allow using uclass_find_device_by_seq() without OF_CONTROL

If OF_CONTROL is not enabled and DM_SEQ_ALIAS is enabled, we must
assign an alias (requested sequence number) to devices that belongs to a
class with the DM_UC_FLAG_SEQ_ALIAS flag. Otherwise
uclass_find_device_by_seq() cannot be used to get/probe a device. In
particular i2c_get_chip_for_busnum() cannot be used.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/include/dm/uclass-internal.h b/include/dm/uclass-internal.h
index 8a4839e..6977995 100644
--- a/include/dm/uclass-internal.h
+++ b/include/dm/uclass-internal.h
@@ -12,6 +12,19 @@
 #include <dm/ofnode.h>
 
 /**
+ * uclass_find_next_free_req_seq() - Get the next free req_seq number
+ *
+ * This returns the next free req_seq number. This is useful only if
+ * OF_CONTROL is not used. The next free req_seq number is simply the
+ * maximum req_seq of the uclass + 1.
+ * This allows assiging req_seq number in the binding order.
+ *
+ * @id:		Id number of the uclass
+ * @return	The next free req_seq number
+ */
+int uclass_find_next_free_req_seq(enum uclass_id id);
+
+/**
  * uclass_get_device_tail() - handle the end of a get_device call
  *
  * This handles returning an error or probing a device as needed.