spi: Updates for v3.18 A quiet release for SPI, mainly driver updates and not too many of them: - Support for dummy transfers (for delays on startup) in drivers using transfer_one(). - Lots of enhancements to the Designware driver to support new Intel SoCs. - Support for newer Renesas chips. - DMA support for the i.MX driver. - One new driver for Broadcom BCM53xx chips.