arm64: dts: qcom: msm8994: Fix the cont_splash_mem address

The default memory map places cont_splash_mem at 3401000, which was
overlooked.. Fix it!

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220319174645.340379-9-konrad.dybcio@somainline.org