NAND core changes:
- Support having the bad block markers in either the first, second or
  last page of a block. The combination of all three location is now
  possible.
- Constification of NAND_OP_PARSER(_PATTERN) elements.
- Generic NAND DT bindings changed to yaml format (can be used to
  check the proposed bindings. First platform to be fully supported:
  sunxi.
- Stopped using several legacy hooks.
- Preparation to use the generic NAND layer with the addition of
  several helpers and the removal of the struct nand_chip from generic
  functions.
- Kconfig cleanup to prepare the introduction of external ECC engines
  support.
- Fallthrough comments.
- Introduction of the SPI-mem dirmap API for SPI-NAND devices.

Raw NAND controller drivers changes:
- nandsim:
  * Switch to ->exec-op().
- meson:
  * Misc cleanups and fixes.
  * New OOB layout.
- Sunxi:
  * A23/A33 NAND DMA support.
- Ingenic:
  * Full reorganization and cleanup.
  * Clear separation between NAND controller and ECC engine.
  * Support JZ4740 an JZ4725B.
- Denali:
  * Clear controller/chip separation.
  * ->exec_op() migration.
  * Various cleanups.
- fsl_elbc:
  * Enable software ECC support.
- Atmel:
  * Sam9x60 support.
- GPMI:
  * Introduce the GPMI_IS_MXS() macro.
- Various trivial/spelling/coding style fixes.