This patch adds support for "imximage" (MX Boot Image)
to the mkimage utility. The imximage is used on the Freescales's
MX.25, MX.35 and MX.51 processors.
Further details under doc/README.imximage.
This patch was tested on a Freescale mx51evk board.
Signed-off-by: Stefano Babic <sbabic@denx.de>