iio:accel: Add STMicroelectronics accelerometers driver

This patch adds a generic accelerometer driver for STMicroelectronics
accelerometers, currently it supports:
LSM303DLH, LSM303DLHC, LIS3DH, LSM330D, LSM330DL, LSM330DLC,
LIS331DLH, LSM303DL, LSM303DLM, LSM330.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
7 files changed