Add support for UNO R4 WiFi board

[karl3200]

WARNING: library ArduinoRS485 claims to run on samd, mbed_portenta, mbed_opta architecture(s) and may be incompatible with your current board which runs on renesas_uno architecture(s).
WARNING: library ArduinoModbus claims to run on megaavr, samd, mbed_nano, mbed_portenta, mbed_opta architecture(s) and may be incompatible with your current board which runs on renesas_uno architecture(s).
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:209:18: error: 'SERIAL_PORT_HARDWARE' was not declared in this scope
 RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);
                  ^~~~~~~~~~~~~~~~~~~~
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:209:18: note: suggested alternative: 'SERIAL_PARITY_MARK'
 RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);
                  ^~~~~~~~~~~~~~~~~~~~
                  SERIAL_PARITY_MARK
In file included from C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:20:0:
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.h:44:30: error: 'A6' was not declared in this scope
 #define RS485_DEFAULT_DE_PIN A6
                              ^
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:209:62: note: in expansion of macro 'RS485_DEFAULT_DE_PIN'
 RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);
                                                              ^~~~~~~~~~~~~~~~~~~~
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.h:44:30: note: suggested alternative: 'A5'
 #define RS485_DEFAULT_DE_PIN A6
                              ^
C:\Users\Karl\Documents\Arduino\libraries\ArduinoRS485\src\RS485.cpp:209:62: note: in expansion of macro 'RS485_DEFAULT_DE_PIN'
 RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);
                                                              ^~~~~~~~~~~~~~~~~~~~

exit status 1