dt-bindings: soc/qcom: Add size constraints on "qcom,rpm-msg-ram"

dt-bindings: soc/qcom: Add size constraints on "qcom,rpm-msg-ram"

The 'phandle-array' type is a bit ambiguous. It can be either just an
array of phandles or an array of phandles plus args. "qcom,rpm-msg-ram" is
the former and needs to constrain each entry to a single phandle value.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240124190744.1554625-1-robh@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>