dm: core: Add size operations on device tree references

Add functions to add size of addresses in the device tree using ofnode
references.

If the size is not set, return FDT_SIZE_T_NONE.

Signed-off-by: Chen Guanqiao <chenguanqiao@kuaishou.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index fa0bd2a..d505333 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -303,6 +303,8 @@
 {
 	int na, ns;
 
+	*size = FDT_SIZE_T_NONE;
+
 	if (ofnode_is_np(node)) {
 		const __be32 *prop_val;
 		u64 size64;
@@ -347,6 +349,15 @@
 	return ofnode_get_addr_index(node, 0);
 }
 
+fdt_size_t ofnode_get_size(ofnode node)
+{
+	fdt_size_t size;
+
+	ofnode_get_addr_size_index(node, 0, &size);
+
+	return size;
+}
+
 int ofnode_stringlist_search(ofnode node, const char *property,
 			     const char *string)
 {