spi: Fixes for v3.11 A couple of things missed during the v3.11 work here: - The spi-bitbang core requires a setup() function even if it does nothing which caused breakage when some empty setup functions were removed after their contents were factored out into the core. While this is clearly silly and will be fixed for v3.12 for now we just restore the functions. - A missing case handled in the s3c64xx driver.