iio: adc: meson-saradc: Make the of_device_id array style consistent

Use only one line for the closing bracket of the last entry and the
opening bracket for the next one to keep the style across the whole
array consistent. Also add a "sentinel" comment to the last entry and
remove the comma to ensure that there won't be any entry after it.
No functional changes.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20200915192621.13202-1-martin.blumenstingl@googlemail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>