tools: kwbimage: Add image version 1 support for Armada XP / 370

This patch integrates the Barebox version of this kwbimage.c file into
U-Boot. As this version supports the image version 1 type for the
Armada XP / 370 SoCs.

It was easier to integrate the existing and known to be working Barebox
source than to update the current U-Boot version to support this
v1 image header format. Now all Marvell MVEBU SoCs are supported:

Image type 0: Kirkwood & Dove
Image type 1: Armada 370 & Armada XP

Please note that the current v1 support has this restuction (same as
has Barebox version):

Not implemented: support for the register headers and secure headers
in v1 images

Tested on Marvell DB-78460-BP eval board.
Signed-off-by: NStefan Roese <sr@denx.de>
Tested-by: NLuka Perkov <luka@openwrt.org>