This patch adds the binding documentation for Spreadtrum SPI
controller device.
Signed-off-by: NLanqing Liu <lanqing.liu@spreadtrum.com>
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>