[Improvement] Use LOG in the examples

[luizvilla]

Description

The LOGGING system of Zephyr is super powerful and could be used in our examples as a means to plot data.

Action

This would require activating the logging in our examples and using them in our work accordingly. A simple way of doing this is described here:
https://blog.golioth.io/debugging-zephyr-for-beginners-printk-and-the-logging-subsystem/

The LOG documentation is here:
https://docs.zephyrproject.org/latest/services/logging/index.html

Maybe we should add examples where we use the LOG to time the code or to debug issues.