Add serial1 alias, firmware name and use 4 pin UART pinmux.
Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Signed-off-by: Caleb Connolly <caleb@connolly.tech>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221016172944.1892206-3-kc@postmarketos.org