rtc: stmp3xxx: Add simple binding for the stmp3xxx-rtc

Signed-off-by: Marek Vasut <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Cc: [e-mail]
Cc: Grant Likely <[e-mail]>
Cc: [e-mail]
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

Documentation/devicetree/bindings/rtc/stmp3xxx-rtc.txt

···
+* STMP3xxx/i.MX28 Time Clock controller
+
+Required properties:
+- compatible: should be one of the following.
+    * "fsl,stmp3xxx-rtc"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- interrupts: rtc alarm interrupt
+
+Example:
+
+rtc@80056000 {
+	compatible = "fsl,imx28-rtc", "fsl,stmp3xxx-rtc";
+	reg = <0x80056000 2000>;
+	interrupts = <29>;
+};

drivers/rtc/rtc-stmp3xxx.c

···
 #include <linux/interrupt.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
+#include <linux/of_device.h>
 
 #include <mach/common.h>
 
···
 #define stmp3xxx_rtc_resume	NULL
 #endif
 
+static const struct of_device_id rtc_dt_ids[] = {
+	{ .compatible = "fsl,stmp3xxx-rtc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rtc_dt_ids);
+
 static struct platform_driver stmp3xxx_rtcdrv = {
 	.probe		= stmp3xxx_rtc_probe,
 	.remove		= stmp3xxx_rtc_remove,
···
 	.driver		= {
 		.name	= "stmp3xxx-rtc",
 		.owner	= THIS_MODULE,
+		.of_match_table = rtc_dt_ids,
 	},
 };