Disable some pre-commit hooks for licenses

It's preferred to keep original license text untouched so
common project code style should not apply to it.

Signed-off-by: Anton Bondarenko <anton.bondarenko@arm.com>

Approved-by: Felix Johnny Thomasmathibalan <felixjohnny.thomasmathibalan@arm.com>
Approved-by: Jakub Sujak <jakub.sujak@arm.com>