arm: ls102xa: Enable Driver Model SPI for ls1021atwr

Enable Driver Model SPI for ls1021atwr board.
DSPI and QSPI only be enabled when boot from QSPI.
DSPI and QSPI are compatible under Driver Model SPI.

Signed-off-by: Haikun Wang <Haikun.Wang@freescale.com>
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Tested-by: Haikun Wang <haikun.wang@freescale.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>