arm64: dts: qcom: sm8450: align MMC node names with dtschema

The bindings expect "mmc" for MMC/SDHCI nodes:

  qcom/sm8450-sony-xperia-nagara-pdx223.dtb: sdhci@8804000: $nodename:0: 'sdhci@8804000' does not match '^mmc(@.*)?$'
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221204094438.73288-1-krzysztof.kozlowski@linaro.org

arch/arm64/boot/dts/qcom/sm8450.dtsi

@@ -3724,7 +3724,7 @@ ufs_mem_phy_lanes: phy@1d87400 {
 			};
 		};
 
-		sdhc_2: sdhci@8804000 {
+		sdhc_2: mmc@8804000 {
 			compatible = "qcom,sm8450-sdhci", "qcom,sdhci-msm-v5";
 			reg = <0 0x08804000 0 0x1000>;