image: bootm: Add OpenRTOS image type

Add separate image type for the Wittenstein OpenRTOS .

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed