tools: kwbimage: don't adjust for image_header for Armada MSYS

tools: kwbimage: don't adjust for image_header for Armada MSYS

For the time being the Armada MSYS SoCs need to use the bin_hdr from the
Marvell U-Boot. Because of this the binary.0 does not contain the image
header that a proper u-boot SPL would so the adjustment introduced by
commit 0fb977d102ea ("tools: kwbimage: Fix dest addr") does not apply.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>