arm64: dts: amlogic: Fix non-compliant SD/SDIO node names

mmc-controller.yaml defines "^mmc(@.*)?$" as node name pattern.
In preparation of adding schema-based validation fix the node name
in two affected files.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/55c53e8d-6b30-51bf-edf6-b5b67887bd0a@gmail.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>