iio: light: cros_ec_light_prox: simplify timestamp channel definition

Use IIO_CHAN_SOFT_TIMESTAMP() to define the timestamp channel instead of
manually filling in the struct iio_chan_spec fields. This makes the code
less verbose and mistake-prone.

Also drop obvious comment while we're at it.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Author: dlech

drivers/iio/light/cros_ec_light_prox.c

@@ -223,14 +223,8 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	/* Timestamp */
 	channel++;
-	channel->type = IIO_TIMESTAMP;
-	channel->channel = -1;
-	channel->scan_index = 1;
-	channel->scan_type.sign = 's';
-	channel->scan_type.realbits = 64;
-	channel->scan_type.storagebits = 64;
+	*channel = IIO_CHAN_SOFT_TIMESTAMP(1);
 
 	indio_dev->channels = state->channels;