The meta-intel BSPs ship with something called a time-limited kernel. Why is it limited?
One important aspect of the Yocto Project is that it is not a distribution - it enables you to build your own distribution. For that reason, Intel BSPs (from the meta-intel layer) ship with a time-limited kernel for evaluation purposes - after 10 days, the kernel will reboot. This kernel is not intended to be used for production systems.
In order to generate a working system, you will need to build your own version. For more information, please see the Quick Start Guide as well as the rest of the Yocto Project documentation set.