iio:adc:max1027: drop of_match_ptr and CONFIG_OF protections

These just prevent the driver being used with ACPI PRP0001
and provide no major benefits.

Part of clearing these out in general in IIO to avoid cut and paste
repetition in new drivers.  Also include mod_devicetable.h as we
directly make use of of_device_id which is defined in there.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Philippe Reynes <tremyfr@yahoo.fr>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

drivers/iio/adc/max1027.c

@@ -14,6 +14,7 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mod_devicetable.h>
 #include <linux/spi/spi.h>
 #include <linux/delay.h>
 
@@ -79,7 +80,6 @@ static const struct spi_device_id max1027_id[] = {
 };
 MODULE_DEVICE_TABLE(spi, max1027_id);
 
-#ifdef CONFIG_OF
 static const struct of_device_id max1027_adc_dt_ids[] = {
 	{ .compatible = "maxim,max1027" },
 	{ .compatible = "maxim,max1029" },
@@ -90,7 +90,6 @@ static const struct of_device_id max1027_adc_dt_ids[] = {
 	{},
 };
 MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids);
-#endif
 
 #define MAX1027_V_CHAN(index, depth)					\
 	{								\
@@ -518,7 +517,7 @@ static int max1027_probe(struct spi_device *spi)
 static struct spi_driver max1027_driver = {
 	.driver = {
 		.name	= "max1027",
-		.of_match_table = of_match_ptr(max1027_adc_dt_ids),
+		.of_match_table = max1027_adc_dt_ids,
 	},
 	.probe		= max1027_probe,
 	.id_table	= max1027_id,