iio: accel: st_accel: fix data-ready line configuration

Remove int2 configuration parameter for LIS3DH, LSM303DLHC, LSM330D,
LSM330DL, LSM330DLC, LSM303AGR, LIS2DH12 and LNG2DM since these devices
export just int1 as data-ready line

Fixes: 23cde4d6 (iio: Added platform data to select the DRDY pin)
Fixes: dcdb0a78 (iio: accel: st_accel: add support to lng2dm)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>