dt-bindings: mvebu-uart: fix documentation

Both UARTs support higher baudrates and are not limited to baudrate 230400.
Only current kernel driver implementation has limitation for both UARTs in
maximal baudrate 230400. This limitation will be removed in next patches.
So remove incorrect information about (hardware) limitation from bindings.

UART1 (standard variant with DT node name 'uart0') has register space
0x12000-0x12018 and not whole size 0x200. So fix also this in example.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: d160c341 ("dt-bindings: mvebu-uart: update documentation with extended UART")
Link: https://lore.kernel.org/r/20210624224909.6350-5-pali@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>