arm64: dts: add stdout-path to chosen node for ls2080a/ls1043a boards

Add a default stdout-path to chosen node for ls2080a/ls1043a boards to
allow booting kernels without specifying console info in bootargs.

Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>