arm64: dts: msm8996: Add SMP2P and APCS nodes

Add SMP2P and APCS DT nodes required for Qualcomm ADSP
Peripheral Image Loader.

Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>