Add a new EVT_POST_PREBOOT event type which is fired in main_loop()
after the preboot command has been executed.
Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>