drivers/rtc/rtc-em3027.c: add device tree support

Set the of_match_table for this driver so that devices can be described in
the device tree. This device is used in the Trimslice and is already
defined in the Trimslice device tree.

Signed-off-by: Peter Robinson <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Cc: Grant Likely <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/rtc/rtc-em3027.c

···
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/module.h>
+#include <linux/of.h>
 
 /* Registers */
 #define EM3027_REG_ON_OFF_CTRL	0x00
···
 	{ "em3027", 0 },
 	{ }
 };
+MODULE_DEVICE_TABLE(i2c, em3027_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id em3027_of_match[] = {
+	{ .compatible = "emmicro,em3027", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, em3027_of_match);
+#endif
 
 static struct i2c_driver em3027_driver = {
 	.driver = {
 		   .name = "rtc-em3027",
+		   .of_match_table = of_match_ptr(em3027_of_match),
 	},
 	.probe = &em3027_probe,
 	.id_table = em3027_id,