arm64: dts: qcom: msm8996: Disable Venus by default

Disable Venus by default to allow booting without closed firmware and
enable it on the boards that didn't previously disable it. This commit
brings no functional difference.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Link: https://lore.kernel.org/r/20210228130831.203765-7-konrad.dybcio@somainline.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>