tools: plbimage support generate rcw file

some system will not generate pbl format u-boot, but require rcw.

Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Reviewed-by: Alison Wang <alison.wang@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
1 file changed