iio: event_monitor: add linear acceleration modifiers

Following the introduction of IIO linear acceleration modifiers, update the
event_monitor tool accordingly.
Signed-off-by: Andrea Merello <andrea.merello@iit.it>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220907132205.28021-4-andrea.merello@iit.itSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

tools/iio/iio_event_monitor.c

@@ -125,6 +125,9 @@ static const char * const iio_modifier_names[] = {
 	[IIO_MOD_PM4] = "pm4",
 	[IIO_MOD_PM10] = "pm10",
 	[IIO_MOD_O2] = "o2",
+	[IIO_MOD_LINEAR_X] = "linear_x",
+	[IIO_MOD_LINEAR_Y] = "linear_y",
+	[IIO_MOD_LINEAR_Z] = "linear_z",
 };
 
 static bool event_is_known(struct iio_event_data *event)