arm64: dts: amlogic: s4: fix mmc clock assignment

arm64: dts: amlogic: s4: fix mmc clock assignment

MMC A and C are mis-represented as having their "clkin0" input connected to
xtal while it is actually connected to the MMC clock, probably in an
attempt to provide 24MHz to the device on this input.

Fix this and assign the clock to 24MHz to actually provide the required
rate.

Fixes: 3ab9d54b5d84 ("arm64: dts: amlogic: enable some device nodes for S4")
Tested-by: Nick Xie <nick@khadas.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260114-amlogic-s4-mmc-fixup-v3-2-a4d3e136b3f2@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>