spi: Updates for v4.19 Quite an active release for the SPI subsystem, lots of small updates and fixes scattered about with highlights including: - 3 wire support in the GPIO driver. - Support for setting a custom memory name in the memory mapped flash drivers. - Support for extended mode in the Freescale DSPI controller. - Support for the non-standard integration with the Microsemi Ocelot platform in the DesignWare driver. - New driver for the SocioNext UniPhier.