spi: Updates for v3.15

A busy release for both cleanups and new drivers this time along with
further factoring out of replicated code into the core:

 - Provide support in the core for DMA mapping transfers - essentially
   all drivers weren't implementing this properly, now there's no
   excuse.
 - Dual and quad mode support for spidev.
 - Fix handling of cs_change in the generic implementation.
 - Remove the S3C_DMA code from the s3c64xx driver now that all the
   platforms using it have been converted to dmaengine.
 - Lots of improvements to the Renesas SPI controllers.
 - Drivers for Allwinner A10 and A31, Qualcomm QUP and Xylinx xtfpga.
 - Removal of the bitrotted ti-ssp driver.

# gpg: Signature made Mon 31 Mar 2014 12:03:09 BST using RSA key ID 7EA229BD
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg:                 aka "Mark Brown <broonie@debian.org>"
# gpg:                 aka "Mark Brown <broonie@kernel.org>"
# gpg:                 aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg:                 aka "Mark Brown <broonie@linaro.org>"
# gpg:                 aka "Mark Brown <Mark.Brown@linaro.org>"