This adds a trace point which prints every loaded image. This includes
bios/firmware/kernel/initradmdisk/pcirom.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190613050937.124903-1-aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>