boards: shields: Adding a new amg88xx shield

Added the new amg88xx sensor shield with designation
amg88xx_grid_eye_eval_shield and updated the overlay, Kconfig and
documentation files accordingly.
The platforms that are compatible with new shield changed, so
sensor sample yaml file was extended for both available shields.

Signed-off-by: Steffen Jahnke <steffen.jahnke@eu.panasonic.com>