dt-bindings: soc: qcom: Add remote-pid binding for GLINK SMEM

Add missing qcom,remote-pid dt binding required for GLINK SMEM
which specifies the remote endpoint of the GLINK edge.

Fixes: 2b41d6c8 ("dt-bindings: soc: qcom: Extend GLINK to cover SMEM")
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>