dm: core: Add a function to find a device by drvdata

It is sometimes useful to find a device in a uclass using only its driver
data. The driver data often indicates the 'subtype' of the device, e,g,
via its compatible string.

Add a function to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/dm/uclass.h b/include/dm/uclass.h
index 74b8e2e..70fca79 100644
--- a/include/dm/uclass.h
+++ b/include/dm/uclass.h
@@ -351,6 +351,20 @@
 int uclass_next_device_check(struct udevice **devp);
 
 /**
+ * uclass_first_device_drvdata() - Find the first device with given driver data
+ *
+ * This searches through the devices for a particular uclass looking for one
+ * that has the given driver data.
+ *
+ * @id: Uclass ID to check
+ * @driver_data: Driver data to search for
+ * @devp: Returns pointer to the first matching device in that uclass, if found
+ * @return 0 if found, -ENODEV if not found, other -ve on error
+ */
+int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
+				struct udevice **devp);
+
+/**
  * uclass_resolve_seq() - Resolve a device's sequence number
  *
  * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a