remoteproc: mediatek: Check the SCP image format

Do a sanity check on the SCP image before loading it to avoid
driver crashes.

Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230210031354.1335-1-tinghan.shen@mediatek.com


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>