There are some small problems in LPC43xx RS485 mode configuration. In...

There are some small problems in LPC43xx RS485 mode configuration. In particular: 1. UART0,2,3 do not have DTR pins (different from UART1), so, Kconfig needs to be adjusted. 2. lpc43_uart.c in RS485 mode only configures DIR pin, but doesn't enable pin output for UART0,2,3. 3. should be option to reverse DIR control pin output polarity. 4. lpc43xx/chip/lpc43_uart.h doesn't have USART3 definitions.  NOTE: I didn't modified and didn't tested USART1, as it has different hardware.  From Vytautas Lukenskas.