iio: Comment that the LSM303D also has the Magnetometer DRDY

Per its datasheet, the LSM303D also features that pin.
Signed-off-by: Marius Hoch <mail@mariushoch.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Hans de Goede <hansg@kernel.org>
Link: https://lore.kernel.org/r/20230415231130.115094-6-mail@mariushoch.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

include/linux/platform_data/st_sensors_pdata.h

@@ -15,7 +15,7 @@
  * @drdy_int_pin: Redirect DRDY on pin 1 (1) or pin 2 (2).
  *	Available only for accelerometer, magnetometer and pressure sensors.
  *	Accelerometer DRDY on LSM330 available only on pin 1 (see datasheet).
- *	Magnetometer DRDY is supported only on LSM9DS0.
+ *	Magnetometer DRDY is supported only on LSM9DS0 and LSM303D.
  * @open_drain: set the interrupt line to be open drain if possible.
  * @spi_3wire: enable spi-3wire mode.
  * @pullups: enable/disable i2c controller pullup resistors.