dt-bindings: arm: cpus: Add kryo780 compatible

Kryo780 is found in SM8450, so add it to the list of cpu compatibles

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211201072745.3969077-2-vkoul@kernel.org