io: adc: ina2xx-adc: Fix sign and use aligned_s64 for timestamp.

Whilst it doesn't actually make any difference because the code
that fills this field doesn't care, timestamps are all signed.
Use the new aligned_s64 instead of open coding alignment to avoid
confusing static analyzers and give slightly cleaner code.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20241215182912.481706-3-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ina2xx-adc.c

@@ -150,7 +150,7 @@ struct ina2xx_chip_info {
 	/* data buffer needs space for channel data and timestamp */
 	struct {
 		u16 chan[4];
-		u64 ts __aligned(8);
+		aligned_s64 ts;
 	} scan;
 };