iio: pressure: bmp280: drop sensor_data array

iio: pressure: bmp280: drop sensor_data array

Drop the sensor_data array from struct bmp280_data and replace it using
local structs in each interrupt handler.

The sensor_data array in struct bmp280_data is not used to share data
between functions and isn't used for DMA, so there isn't really a need
to have it in the struct. Instead, we can use the struct pattern for
scan data in each interrupt handler. This has the advantage of allowing
us to see the actual layout of each scan buffer for each different type
of supported sensor. It also avoid juggling values between local
variables and the array which makes the code a bit simpler by avoiding
some extra assignments.

We can also drop the BME280_NUM_MAX_CHANNELS macro as it is no longer
used.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Link: https://lore.kernel.org/linux-iio/20250421135540.1a667221@jic23-huawei/
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://patch.msgid.link/20250422-iio-pressure-bmp280-rework-push-to-buffers-v1-1-ee722f29aeca@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>