hw/sensor: Add sensor_node_cfg structure
hw/sensor: Add sensor_node_cfg structure

To create os_dev which is a bus node for sensor device we need to pass
both node configuration and sensor interface. To make this easier,
there's now sensor_node_cfg struc provided which contains both data and
can be passed when creating os_dev.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core