arm64: dts: renesas: white-hawk: Move aliases and chosen

The serial console port on White Hawk is located on the CPU board.
Hence move the aliases and chosen nodes containing serial console
configuration from the main White Hawk DTS file to the DTS file that
describes the CPU board.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/b03b74f4b5ee3c3e828e753beb334ec43162c132.1662715538.git.geert+renesas@glider.be