The SPI core provides infrastructure for standard message queueing so use
that instead of handling everything in the driver. This simplifies the
driver.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>