ls102xa: changing a few targets' configurations.

Enable hypervisors utilizing the ARMv7 virtualization extension
on the LS1021A-QDS/TWR boards with the A7 core tile, we add the
required configuration variable.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>