iio: pressure: dlhl60d: Don't take garbage into consideration when reading data

Both pressure and temperature are 24-bit long. Use proper accessors
instead of overlapping readings.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220726142048.4494-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>