iio: accel: fxls8962af: add padding to regmap for SPI

Add missing don't care padding between address and
data for SPI transfers

Fixes: a3e0b518 ("iio: accel: add support for FXLS8962AF/FXLS8964AF accelerometers")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20211220125144.3630539-1-sean@geanix.com


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