iio: hid-sensors: Added Proximity Sensor Driver

Added usage id processing for Proximity (Human Presence).
This uses IIO interfaces for triggered buffer to present data
to user mode. This uses HID sensor framework for registering
callback events from the sensor hub.

Signed-off-by: Archana Patni <archana.patni@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>