Pull NAND changes from Boris Brezillon:

"
  Core changes:
  * Fix NAND_CMD_NONE handling in nand_command[_lp]() hooks
  * Introduce the ->exec_op() infrastructure
  * Rework NAND buffers handling
  * Fix ECC requirements for K9F4G08U0D
  * Fix nand_do_read_oob() to return the number of bitflips
  * Mark K9F1G08U0E as not supporting subpage writes

  Driver changes:
  * MTK: Rework the driver to support new IP versions
  * OMAP OneNAND: Full rework to use new APIs (libgpio, dmaengine) and fix
    DT support
  * Marvell: Add a new driver to replace the pxa3xx one
"