dt-bindings: mmc: sdhci-msm: Document QCM2290 SDHCI

Document the SDHCI on QCM2290.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230314-topic-2290_compats-v1-4-47e26c3c0365@linaro.org


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>