The baud rate for the RAVPower RP-WD03 is 57600, not 115200.
Since this is the default from mt7620n.dtsi, the chosen node can
simply be removed from the device DTS.
Fixes: 5ef79af4f8 ("ramips: add support for Ravpower WD03")
Suggested-by: Russell Morris <rmorris@rkmorris.us>
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>