spi: Fixes for v4.10

The usual small smattering of driver specific fixes.  A few bits that
stand out here:

 - The R-Car patches adding fallbacks are just adding new compatible
   strings to the driver so that device trees are written in a more
   robustly future proof fashion, this isn't strictly a fix but it's
   just new IDs and it's better to get it into mainline sooner to
   improve the ABI.
 - The DesignWare "switch to new API part 2" patch is actually a
   misleadingly titled fix for a bit that got missed in the original
   conversion.
Merge remote-tracking branch 'spi/fix/sh-msiof' into spi-linus