Merge tag 'nand/for-4.21' of git://git.infradead.org/linux-mtd into mtd/next

NAND core changes:
- kernel-doc miscellaneous fixes.
- Third batch of fixes/cleanup to the raw NAND core impacting various
  controller drivers (ams-delta, marvell, fsmc, denali, tegra, vf610):
  * Stopping to pass mtd_info objects to internal functions
  * Reorganizing code to avoid forward declarations
  * Dropping useless test in nand_legacy_set_defaults()
  * Moving nand_exec_op() to internal.h
  * Adding nand_[de]select_target() helpers
  * Passing the CS line to be selected in struct nand_operation
  * Making ->select_chip() optional when ->exec_op() is implemented
  * Deprecating the ->select_chip() hook
  * Moving the ->exec_op() method to nand_controller_ops
  * Moving ->setup_data_interface() to nand_controller_ops
  * Deprecating the dummy_controller field
  * Fixing JEDEC detection
  * Providing a helper for polling GPIO R/B pin

Raw NAND chip drivers changes:
- Macronix:
  * Flagging 1.8V AC chips with a broken GET_FEATURES(TIMINGS)

Raw NAND controllers drivers changes:
- Ams-delta:
  * Fixing the error path
  * SPDX tag added
  * May be compiled with COMPILE_TEST=y
  * Conversion to ->exec_op() interface
  * Dropping .IOADDR_R/W use
  * Use GPIO API for data I/O
- Denali:
  * Removing denali_reset_banks()
  * Removing ->dev_ready() hook
  * Including <linux/bits.h> instead of <linux/bitops.h>
  * Changes to comply with the above fixes/cleanup done in the core.
- FSMC:
  * Adding an SPDX tag to replace the license text
  * Making conversion from chip to fsmc consistent
  * Fixing unchecked return value in fsmc_read_page_hwecc
  * Changes to comply with the above fixes/cleanup done in the core.
- Marvell:
  * Preventing timeouts on a loaded machine (fix)
  * Changes to comply with the above fixes/cleanup done in the core.
- OMAP2:
  * Pass the parent of pdev to dma_request_chan() (fix)
- R852:
  * Use generic DMA API
- sh_flctl:
  * Converting to SPDX identifiers
- Sunxi:
  * Write pageprog related opcodes to the right register: WCMD_SET (fix)
- Tegra:
  * Stop implementing ->select_chip()
- VF610:
  * Adding an SPDX tag to replace the license text
  * Changes to comply with the above fixes/cleanup done in the core.
- Various trivial/spelling/coding style fixes.

SPI-NAND drivers changes:
- Removing the depreacated mt29f_spinand driver from staging.
- Adding support for:
  * Toshiba TC58CVG2S0H
  * GigaDevice GD5FxGQ4xA
  * Winbond W25N01GV