dt-bindings: arm: qcom: document SM8650 and the reference boards

Document the SM8650 SoC and based MTP (Mobile Test Platforms) and QRD
(Qualcomm Reference Device) boards.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20231130-topic-sm8650-upstream-dt-v5-1-b25fb781da52@linaro.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>