iio: cros_ec_sensors: Fix alignment of buffer in iio_push_to_buffers_with_timestamp()

iio: cros_ec_sensors: Fix alignment of buffer in iio_push_to_buffers_with_timestamp()

[ Upstream commit 8dea228b174ac9637b567e5ef54f4c40db4b3c41 ]

The samples buffer is passed to iio_push_to_buffers_with_timestamp()
which requires a buffer aligned to 8 bytes as it is assumed that
the timestamp will be naturally aligned if present.

Fixes tag is inaccurate but prior to that likely manual backporting needed
(for anything before 4.18) Earlier than that the include file to fix is
drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h:
commit 974e6f02e27 ("iio: cros_ec_sensors_core: Add common functions
for the ChromeOS EC Sensor Hub.") present since kernel stable 4.10.
(Thanks to Gwendal for tracking this down)

Fixes: 5a0b8cb46624c ("iio: cros_ec: Move cros_ec_sensors_core.h in /include")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org
Link: https://lore.kernel.org/r/20210501171352.512953-7-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>