samples: add environmental sensing sample for Arduino 101

The ARC application collects temperature, humidity and pressure data from
a set of sensors connected to the Arduino 101 and sends it to the x86 core
through IPM. The collected data is also displayed on a Grove LCD.

The x86 application exposes the received sensor data as a simple Bluetooth
Environmental Sensing Service.

This version of the sample does not offer notifications when the sensor data
values change.

Change-Id: Iee456d5d2455c7ccb7c5923ef3c94ecb20b5cecb
Signed-off-by: Bogdan Davidoaia <bogdan.m.davidoaia@intel.com>