mtd: nand: tegra: convert to driver model and live tree

mtd: nand: tegra: convert to driver model and live tree

The Tegra NAND driver recently got broken by ongoing driver model resp.
live tree migration work:

NAND:  Could not decode nand-flash in device tree
Tegra NAND init failed
0 MiB

A patch for NAND uclass support was proposed about a year ago:
https://patchwork.ozlabs.org/patch/722282/

It was not merged and I do not see on-going work for this.

This commit just provides a driver model probe hook to retrieve further
configuration from the live device tree. As there is no NAND ulass as of
yet (ab)using UCLASS_MTD. Once UCLASS_NAND is supported, it would be
possible to migrate to it.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>