arm64: dts: qcom: sc8280xp: Define uart2

Add the definition for uart2 for sc8280xp devices.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230326233812.28058-4-steev@kali.org