iio: adc: ads8688: Switch to mod_devicetable.h for struct of_device_id definition

of.h was only included to get access to this structure, so include the
correct header directly instead.
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240218173323.1023703-5-jic23@kernel.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ti-ads8688.c

@@ -11,7 +11,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/mod_devicetable.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>