ARM: dts: qcom: sdx55-mtp: add MPSS remoteproc memory-region

The MPSS PAS remoteproc bindings require memory-region.  The MPSS PAS
device node is disabled, but schema still asks for it.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221118113747.56700-1-krzysztof.kozlowski@linaro.org