thermal: imx_sc_thermal: Add hwmon support

Expose i.MX SC thermal sensors as HWMON devices.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1585192411-25593-1-git-send-email-Anson.Huang@nxp.com

drivers/thermal/imx_sc_thermal.c

@@ -14,6 +14,7 @@
 #include <linux/thermal.h>
 
 #include "thermal_core.h"
+#include "thermal_hwmon.h"
 
 #define IMX_SC_MISC_FUNC_GET_TEMP	13
 
@@ -115,6 +116,9 @@ static int imx_sc_thermal_probe(struct platform_device *pdev)
 			ret = PTR_ERR(sensor->tzd);
 			break;
 		}
+
+		if (devm_thermal_add_hwmon_sysfs(sensor->tzd))
+			dev_warn(&pdev->dev, "failed to add hwmon sysfs attributes\n");
 	}
 
 	of_node_put(sensor_np);