arm64: dts: qcom: sm6350: Add wifi node

Add a node describing the wifi hardware found on sm6350.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220325101841.172304-1-luca.weiss@fairphone.com