The SabreSD platform is available with i.MX6Q or i.MX6DL. This patch adds the
support of the i.MX6DL. The config file and the board directory are renamed
to remove the reference to the MX6Q.

Signed-off-by: Pierre Aubert <p.aubert@staubli.com>
CC: Stefano Babic <sbabic@denx.de>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>