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/include/tee/optee.h b/include/tee/optee.h
index affa937..ebdfe5e 100644
--- a/include/tee/optee.h
+++ b/include/tee/optee.h
@@ -71,9 +71,9 @@
 #endif
 
 #if defined(CONFIG_OPTEE) && defined(CONFIG_OF_LIBFDT)
-int optee_copy_fdt_nodes(const void *old_blob, void *new_blob);
+int optee_copy_fdt_nodes(void *new_blob);
 #else
-static inline int optee_copy_fdt_nodes(const void *old_blob, void *new_blob)
+static inline int optee_copy_fdt_nodes(void *new_blob)
 {
 	return 0;
 }