iio: magnetometer: mmc35240: fix SET/RESET sequence

The RESET operation invoked in the last instance will align
in the natural way all 3 axis and the chip top view.

Without this, north and south are swapped.

Signed-off-by: Viorel Suman <viorel.suman@intel.com>
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>