arm64: dts: amlogic: a1: use correct node name for mmc controller

This fixes the following:
sd@10000: $nodename:0: 'sd@10000' does not match '^mmc(@.*)?$'

Tested-by: Christian Hewitt <christianshewitt@gmail.com>
Link: https://lore.kernel.org/r/20240606-topic-amlogic-upstream-bindings-fixes-dts-v1-10-62e812729541@linaro.org


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