spi: Updates for v3.12 Business as usual for SPI - some new drivers, lots of fixes and updates to existing drivers plus some new framework features. Notable changes are: - Support for dual and quad data lines, commonly used by flash chips to improve performance, from Wang Yuhang. - Factored out a common pattern for runtime PM implementation into the core saving a bunch of code. - A particularly nice set of updates to the ep93xx driver from H Hartley Sweeten, modernising it and reducing the code size a lot. - New drivers for Blackfin v3, EFM32, Freescale DSPI and TI QSPI.