hw/arm/bcm2836: Mark the bcm2836 / bcm2837 devices with user_creatable = false

hw/arm/bcm2836: Mark the bcm2836 / bcm2837 devices with user_creatable = false

These devices are currently causing some problems when a user is trying
to hot-plug or introspect them during runtime. Since these devices can
not be instantiated by the user at all (they need to be wired up in code
instead), we should mark them with user_creatable = false anyway, then we
avoid at least the crashes with the hot-plugging. The introspection problem
will be handled by a separate patch.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-id: 1531415537-26037-1-git-send-email-thuth@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>