[nrf fromtree] soc: nordic: nrf54h: bicrgen: add crc calculation to bicr field

The BICR structure has a field at the end for a CRC of the preceeding
structure. Add computation and population of the CRC field to the
bicrgen.py script, and add a check for the validity of the CRC field,
if present, when parsing a BICR structure.

Signed-off-by: Bjarki Arge Andreasen <bjarki.andreasen@nordicsemi.no>

(cherry picked from commit a6d085d891e28d229cd6c1157bf4a823ec2bac48)

Author: bjarki-andreasen