dt-bindings: mmc: mmci: Add st,stm32mp25-sdmmc2 compatible

For STM32MP25, we'll need to distinguish how is managed the delay block.
This is done through a new comptible dedicated for this SoC, as the
delay block registers are located in SYSCFG peripheral.
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230619115120.64474-2-yann.gautier@foss.st.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/arm,pl18x.yaml

@@ -53,10 +53,11 @@ properties:
         items:
           - const: arm,pl18x
           - const: arm,primecell
-      - description: Entry for STMicroelectronics variant of PL18x.
-          This dedicated compatible is used by bootloaders.
+      - description: Entries for STMicroelectronics variant of PL18x.
         items:
-          - const: st,stm32-sdmmc2
+          - enum:
+              - st,stm32-sdmmc2
+              - st,stm32mp25-sdmmc2
           - const: arm,pl18x
           - const: arm,primecell