dm: add cells_count parameter in *_count_phandle_with_args

The cell_count argument is required when cells_name is NULL.

This patch adds this parameter in live tree API
- of_count_phandle_with_args
- ofnode_count_phandle_with_args
- dev_count_phandle_with_args

This parameter solves issue when these API is used to count
the number of element of a cell without cell name. This parameter
allow to force the size cell.

For example:
  count = dev_count_phandle_with_args(dev, "array", NULL, 3);

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/phy/phy-uclass.c b/drivers/phy/phy-uclass.c
index 8f456f3..f344e94 100644
--- a/drivers/phy/phy-uclass.c
+++ b/drivers/phy/phy-uclass.c
@@ -214,7 +214,7 @@
 	if (!dev_read_prop(dev, "phys", NULL))
 		return 0;
 
-	count = dev_count_phandle_with_args(dev, "phys", "#phy-cells");
+	count = dev_count_phandle_with_args(dev, "phys", "#phy-cells", 0);
 	if (count < 1)
 		return count;