Currently driver supports only configuration of GPIO CS through
platform data. This patch enhances the driver to configure GPIO
CS through DT. Also update the DT binding documentation to
reflect the availability of cs-gpios.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>