Ingenic JZ4755 SoC (JZ4750D family) has three UARTs.
So we can give to the user choose which one of them
to use for low level debug (debug_ll) output.
Also this commit adapts the only JZ4755 board
(Ritmix RZX50) for using the new debug_ll port
selection.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>