bootstd: Export bootdev_get_from_blk()

Export this function so it can be used from other files.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/bootdev-uclass.c b/boot/bootdev-uclass.c
index a4e1d79..65a3b89 100644
--- a/boot/bootdev-uclass.c
+++ b/boot/bootdev-uclass.c
@@ -319,7 +319,7 @@
 	return 0;
 }
 
-static int bootdev_get_from_blk(struct udevice *blk, struct udevice **bootdevp)
+int bootdev_get_from_blk(struct udevice *blk, struct udevice **bootdevp)
 {
 	struct udevice *parent = dev_get_parent(blk);
 	struct udevice *bootdev;
diff --git a/include/bootdev.h b/include/bootdev.h
index 991b622..12c90c4 100644
--- a/include/bootdev.h
+++ b/include/bootdev.h
@@ -402,6 +402,15 @@
 int bootdev_get_sibling_blk(struct udevice *dev, struct udevice **blkp);
 
 /**
+ * bootdev_get_from_blk() - Get the bootdev given a block device
+ *
+ * @blk: Block device to check
+ * @bootdebp: Returns the bootdev found, if any
+ * Return 0 if OK, -ve on error
+ */
+int bootdev_get_from_blk(struct udevice *blk, struct udevice **bootdevp);
+
+/**
  * bootdev_unbind_dev() - Unbind a bootdev device
  *
  * Remove and unbind a bootdev device which is a child of @parent. This should