dt-bindings: sdhci-fujitsu: Add compatible string for F_SDH30_E51

Add a compatible string for F_SDH30_E51 IP to the documentation.
Since this IP is transferred to Socionext, so append it as vendor name.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221111081033.3813-4-hayashi.kunihiko@socionext.com


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