ARM: dts: rockchip: Add alternate UART pins to rv1126

Add uart3m2_xfer and uart4m2_xfer pins for Rockchip RV1126. These are
used as serial ports for the indicator and Zigbee radio on the iHost.

Signed-off-by: Tim Lunn <tim@feathertop.org>
Link: https://lore.kernel.org/r/20231203124004.2676174-2-tim@feathertop.org


Signed-off-by: Heiko Stuebner <heiko@sntech.de>