iio: imu: adis16475: correct copy paste mistake in comment block

The minimal advised lower rate for adis16475 compatible devices is
1900HZ and not 4000HZ. Set that right in the comments so that it does
not generate any confusion.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230213153208.1027602-1-nuno.sa@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/adis16475.c

@@ -326,11 +326,11 @@ static int adis16475_set_freq(struct adis16475 *st, const u32 freq)
 
 		/*
 		 * This is not an hard requirement but it's not advised to run the IMU
-		 * with a sample rate lower than 4000Hz due to possible undersampling
+		 * with a sample rate lower than 1900Hz due to possible undersampling
 		 * issues. However, there are users that might really want to take the risk.
 		 * Hence, we provide a module parameter for them. If set, we allow sample
-		 * rates lower than 4KHz. By default, we won't allow this and we just roundup
-		 * the rate to the next multiple of the input clock bigger than 4KHz. This
+		 * rates lower than 1.9KHz. By default, we won't allow this and we just roundup
+		 * the rate to the next multiple of the input clock bigger than 1.9KHz. This
 		 * is done like this as in some cases (when DEC_RATE is 0) might give
 		 * us the closest value to the one desired by the user...
 		 */