iio: adis16400: adis16300 has product ID and serial number

The ADIS16300 has the product ID and serial number registers, they are just
not documented. Set the appropriate flags so the driver makes use of them.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/iio/imu/adis16400_core.c

@@ -696,7 +696,8 @@ static struct adis16400_chip_info adis16400_chips[] = {
 	[ADIS16300] = {
 		.channels = adis16300_channels,
 		.num_channels = ARRAY_SIZE(adis16300_channels),
-		.flags = ADIS16400_HAS_SLOW_MODE,
+		.flags = ADIS16400_HAS_PROD_ID | ADIS16400_HAS_SLOW_MODE |
+				ADIS16400_HAS_SERIAL_NUMBER,
 		.gyro_scale_micro = IIO_DEGREE_TO_RAD(50000), /* 0.05 deg/s */
 		.accel_scale_micro = 5884,
 		.temp_scale_nano = 140000000, /* 0.14 C */