arm64: dts: qcom: sm8350: align MMC node names with DT schema

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

  sm8350-sony-xperia-sagami-pdx214.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>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221223161835.112079-4-krzysztof.kozlowski@linaro.org