Replace 'whitelist' with 'allow'

Let's use more inclusive language here and avoid terms
that are frowned upon nowadays.

Message-Id: <20220711095300.60462-1-thuth@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>