lib: optee: migration optee_copy_fdt_nodes for OF_LIVE support

The optee_copy_fdt_nodes is only used to copy op-tee nodes
of U-Boot device tree (from gd->fdt_blob when OF_LIVE is not activated)
to external device tree but it is not compatible with OF_LIVE.

This patch migrates all used function fdt_ functions to read node on
old_blob to ofnode functions, compatible with OF_LIVE and remove this
parameter "old_blob".

The generated "device tree" is checked on stm32mp platform with OF_LIVE
activated.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/common/image-fdt.c b/common/image-fdt.c
index a287b66..d50e1ba 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -562,7 +562,7 @@
 		goto err;
 	}
 
-	fdt_ret = optee_copy_fdt_nodes(gd->fdt_blob, blob);
+	fdt_ret = optee_copy_fdt_nodes(blob);
 	if (fdt_ret) {
 		printf("ERROR: transfer of optee nodes to new fdt failed: %s\n",
 		       fdt_strerror(fdt_ret));