spl: add a fdt_addr field to spl_image_info

When loading a full U-Boot with detached device-tree using the SPL FIT
backend, we should store the address of the FDT loaded as part of the
SPL image info: this allows us to fixup the FDT with additional info
we may want to propagate onward.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/spl.h

@@ -25,6 +25,9 @@ struct spl_image_info {
 	u8 os;
 	ulong load_addr;
 	ulong entry_point;
+#if CONFIG_IS_ENABLED(LOAD_FIT)
+	void *fdt_addr;
+#endif
 	u32 size;
 	u32 flags;
 	void *arg;