[Buildroot] [PATCH 1/1] uboot-tools: add option for dumpimage

[Carlos Santos]

From: Paulo Zaneti <paulo.zaneti at datacom.ind.br>

> The tool dumpimage extracts data from U-Boot images.
> U-Boot added dumpimage tool on release 2014.01.
> This commit allows installation on target and host.
> 
> Signed-off-by: Paulo Zaneti <paulo.zaneti at datacom.ind.br>
Tested-by: Carlos Santos <casantos at datacom.ind.br>

Built host (x86_64) and target (PowerPC) packages and verified that
both are compiled and installed properly.

Signed-off-by: Carlos Santos <casantos at datacom.ind.br>