Merge tag 'spi-nor/for-4.13' into MTD

From Cyrille:
"""
This pull request contains the following notable changes:
- introduce support to the SPI 1-2-2 and 1-4-4 protocols.
- introduce support to the Double Data Rate (DDR) mode.
- introduce support to the Octo SPI protocols.
- add support to new memory parts for Spansion, Macronix and Winbond.
- add fixes for the Aspeed, STM32 and Cadence QSPI controler drivers.
- clean up the st_spi_fsm driver.
"""