arm64: dts: sc7180: Add Venus firmware subnode

This adds Venus firmware subnode for non-TZ platform.

Reviewed-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org>
Link: https://lore.kernel.org/r/1579006416-11599-5-git-send-email-dikshita@codeaurora.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>