ARM: dts: qcom: sdx65: Add reserved memory nodes

Add reserved memory nodes to the SDX65 dtsi as defined by
the memory map.

Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1649670615-21268-2-git-send-email-quic_rohiagar@quicinc.com