arm64: dts: qcom: msm8976: correct MMC unit address

Match unit-address to reg entry to fix dtbs W=1 warnings:

  Warning (simple_bus_reg): /soc@0/mmc@7824000: simple-bus unit address format error, expected "7824900"
  Warning (simple_bus_reg): /soc@0/mmc@7864000: simple-bus unit address format error, expected "7864900"
  Warning (simple_bus_reg): /soc@0/mmc@7a24000: simple-bus unit address format error, expected "7a24900"

Fixes: 0484d3ce ("arm64: dts: qcom: Add DTS for MSM8976 and MSM8956 SoCs")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230419211856.79332-7-krzysztof.kozlowski@linaro.org