iio: pressure: ms5611: fixed value compensation bug

When using multiple instances of this driver the compensation PROM was
overwritten by the last initialized sensor. Now each sensor has own PROM
storage.

Signed-off-by: Mitja Spes <mitja@lxnav.com>
Fixes: 9690d81a ("iio: pressure: ms5611: add support for MS5607 temperature and pressure sensor")
Link: https://lore.kernel.org/r/20221021135827.1444793-2-mitja@lxnav.com


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