iio: imu: inv_mpu6050: align buffer for timestamp

Align the buffer used with iio_push_to_buffers_with_timestamp() to
ensure the s64 timestamp is aligned to 8 bytes.

Fixes: 0829edc4 ("iio: imu: inv_mpu6050: read the full fifo when processing data")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250417-iio-more-timestamp-alignment-v1-7-eafac1e22318@baylibre.com


Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>