ata: fsl_ahci: Add sata DM support for Freescale powerpc socs

This patch is to support Freescale sata driver with dts initialized.
Also resolved the following problems.

===================== WARNING ======================
This board does not use CONFIG_DM_SCSI. Please update
the storage controller to use CONFIG_DM_SCSI before the v2019.07 release.
Failure to update by the deadline may result in board removal.
See doc/driver-model/MIGRATION.txt for more info.
====================================================

Signed-off-by: Peng Ma <peng.ma@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>