imxrt1020: migrate to build system included -u-boot.dtsi

Migrate to using automatic build system included -u-boot.dtsi device
tree include files.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Tested-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
2 files changed