binman: Only write FDT once per node

binman: Only write FDT once per node

Due to an extra level of indentation, the "data" property containing the
FDT was being written repeatedly after every other property in the node.
This caused the generated FIT image to be invalid.

Move the block up one level, so the property is added exactly once.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>