iio: chemical: pms7003: use aligned_s64 for timestamp

Follow the pattern of other drivers and use aligned_s64 for the
timestamp. This will ensure that the timestamp is correctly aligned on
all architectures.

Also move the unaligned.h header while touching this since it was the
only one not in alphabetical order.

Fixes: 13e94563 ("iio:chemical:pms7003: Fix timestamp alignment and prevent data leak.")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250417-iio-more-timestamp-alignment-v1-4-eafac1e22318@baylibre.com


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