iio: accel: bma400: Ensure VDDIO is enable defore reading the chip ID.

The regulator enables were after the check on the chip variant, which was
very unlikely to return a correct value when not powered.
Presumably all the device anyone is testing on have a regulator that
is already powered up when this code runs for reasons beyond the scope
of this driver. Move the read call down a few lines.

Fixes: 3cf7ded1 ("iio: accel: bma400: basic regulator support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Robertson <dan@dlrobertson.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221002144133.3771029-1-jic23@kernel.org