arm64: dts: qcom: sm8250-edo: Set UART alias and stdout-path

The GENI UART driver requires one specifies a numeric alias. Do so and
set the stdout-path to route the console to the debug uart in the microSD
slot by default.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230912-topic-edoconsole-v1-1-b392ea67e539@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>