ARM: dts: nuvoton: wpcm450: Add missing aliases for serial0/serial1

Without these, /chosen/stdout-path = "serial0:115200n8" does not work.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221008130822.1227104-1-j.neuschaefer@gmx.net


Signed-off-by: Joel Stanley <joel@jms.id.au>