With the generic DMA device tree helper supported by mxs-dma driver,
client devices only need to call dma_request_slave_channel() for
requesting a DMA channel from dmaengine.

Since mxs is a DT only platform now, along with the changes, the non-DT
case handling in probe function also gets removed.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>

Add "clock-frequency" property, which allows configuring the SPI block's
base speed.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMarek Vasut <marex@denx.de>
Acked-by: NChris Ball <cjb@laptop.org>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>