iio: pressure: mprls0025pa: use aligned_s64 for timestamp

Follow the pattern of other drivers and use aligned_s64 for the
timestamp. This will ensure the struct itself it also 8-byte aligned.

While touching this, convert struct mpr_chan to an anonymous struct
to consolidate the code a bit to make it easier for future readers.

Fixes: 713337d ("iio: pressure: Honeywell mprls0025pa pressure sensor")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250418-iio-more-timestamp-alignment-v2-2-d6a5d2b1c9fe@baylibre.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/pressure/mprls0025pa.h

@@ -34,16 +34,6 @@ struct iio_dev;
 struct mpr_data;
 struct mpr_ops;
 
-/**
- * struct mpr_chan
- * @pres: pressure value
- * @ts: timestamp
- */
-struct mpr_chan {
-	s32 pres;
-	s64 ts;
-};
-
 enum mpr_func_id {
 	MPR_FUNCTION_A,
 	MPR_FUNCTION_B,
@@ -69,6 +59,8 @@ enum mpr_func_id {
  *       reading in a loop until data is ready
  * @completion: handshake from irq to read
  * @chan: channel values for buffered mode
+ * @chan.pres: pressure value
+ * @chan.ts: timestamp
  * @buffer: raw conversion data
  */
 struct mpr_data {
@@ -87,7 +79,10 @@ struct mpr_data {
 	struct gpio_desc	*gpiod_reset;
 	int			irq;
 	struct completion	completion;
-	struct mpr_chan		chan;
+	struct {
+		s32 pres;
+		aligned_s64 ts;
+	} chan;
 	u8	    buffer[MPR_MEASUREMENT_RD_SIZE] __aligned(IIO_DMA_MINALIGN);
 };