Merge tag 'spi-nor/for-4.12-v2' of git://github.com/spi-nor/linux into MTD

From Cyrille:
"""
This pull request contains the following notable changes:
- fixes in the hisi SPI controller driver.
- fixes in the intel SPI controller driver.
- fixes in the Mediatek SPI controller driver.
- fixes to some SPI flash memories not supported the Chip Erase command.
- add support to some new memory parts (Winbond, Macronix, Micron, ESMT).
- add new driver for the STM32 QSPI controller.
"""