spi: Updates for v4.14 A fairly quiet release for the SPI subsystem: - Move to using IDR for allocating bus numbers. - Modernisation of the ep93xx driver, removing a lot of open coding and using the framework more. - The tools have been moved to use the standard tools build system and an install target added (there will be a fairly trivial conflict with tip resulting from the changes in the main tools Makefile). - A refactoring of the Qualcomm QUP driver which enables new variants to be supported. - Explicit support for the Freescale i.MX53 and i.MX6 SPI, Renesas R-Car H3 and Rockchip RV1108 controllers. There's also a trivial add/add conflict in spi.c with the ACPI tree adding a header for some Apple support and the IDR code needing a header too.