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/core/of_access.c b/drivers/core/of_access.c
index bcf1644..0a12e9b 100644
--- a/drivers/core/of_access.c
+++ b/drivers/core/of_access.c
@@ -756,10 +756,11 @@
 }
 
 int of_count_phandle_with_args(const struct device_node *np,
-			       const char *list_name, const char *cells_name)
+			       const char *list_name, const char *cells_name,
+			       int cell_count)
 {
-	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
-					    -1, NULL);
+	return __of_parse_phandle_with_args(np, list_name, cells_name,
+					    cell_count, -1, NULL);
 }
 
 static void of_alias_add(struct alias_prop *ap, struct device_node *np,