dt-bindings: mmc: sdhci-msm: add MSM8998

Add a MSM8998-specific SDCC compatible, because using only a generic
qcom,sdhci-msm-v4 fallback is deprecated.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20220714091042.22287-2-krzysztof.kozlowski@linaro.org


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