ci: bsim tests: Also trigger on common nordic DT changes

The bsim boards, just like the real ones, use the common
nordic DT definitions, but this were not triggering CI.
Some issues got in main due to this. Let's be sure to trigger
this workflow also when the releavnt DT files are changed.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>