tools: kwboot: Fix patching of SPI/NOR XIP images

Marvell BootROM interprets execaddr of SPI/NOR XIP images as relative byte
offset from the from the beginning of the flash device. So if data image
offset and execute offset are not same then it is needed to adjust them
also in DDR RAM.

Fixes: f2c644e0 ("tools: kwboot: Patch destination address to DDR area for SPI image")
Signed-off-by: Pali Rohár <pali@kernel.org>