board: freescale: ls1012a2g5rdb: enable network support on ls1012a2g5rdb

This patch enables ethernet support for ls1012a2g5rdb.

Signed-off-by: Calvin Johnson <calvin.johnson@nxp.com>
Signed-off-by: Bhaskar Upadhaya <Bhaskar.Upadhaya@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>