spi: rockchip: support "sleep" pin configuration

In the pattern of many other devices, support a system-sleep pin
configuration.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-rockchip.c

@@ -17,6 +17,7 @@
 #include <linux/dmaengine.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
 #include <linux/pm_runtime.h>
@@ -843,6 +844,8 @@ static int rockchip_spi_suspend(struct device *dev)
 		clk_disable_unprepare(rs->apb_pclk);
 	}
 
+	pinctrl_pm_select_sleep_state(dev);
+
 	return ret;
 }
 
@@ -852,6 +855,8 @@ static int rockchip_spi_resume(struct device *dev)
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct rockchip_spi *rs = spi_master_get_devdata(master);
 
+	pinctrl_pm_select_default_state(dev);
+
 	if (!pm_runtime_suspended(dev)) {
 		ret = clk_prepare_enable(rs->apb_pclk);
 		if (ret < 0)