dt-bindings: mmc: sdhci-msm: Document the SM6115 compatible

Document the compatible for SDHCI on SM6115.

Signed-off-by: Adam Skladowski <a39.skl@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220815100952.23795-4-a39.skl@gmail.com


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