uboot-imx

MLK-18147-2 mx6sabreauto/sabresd: Update mx6dq/dqp/dl/s sabre boards codes

Porting the mx6dq/dqp/dl/s sabresd and sabreauto codes from v2018.03
The major change is moving back to non-SPL mode for sabre boards.
which means all old things like DCD, plugin are added back for each
platform. This inherits the way used in v2018.03

Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit 3a3a0f07c85b0ae86b18709445206db0310c3b63)