Remove SERIAL_PORT_2 code duplication

Marlin/Configuration.h

@@ -182,7 +182,6 @@
  * :[2400, 9600, 19200, 38400, 57600, 115200, 250000, 500000, 1000000]
  */
 #define BAUDRATE 250000
-#define BAUDRATE_2 500000  // For ESP8266
 //#define BAUD_RATE_GCODE     // Enable G-code M575 to set the baud rate
 
 /* EXP1 Header
@@ -205,8 +204,8 @@
  * Currently Ethernet (-2) is only supported on Teensy 4.1 boards.
  * :[-2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-//#define SERIAL_PORT_2 -1
-//#define BAUDRATE_2 250000   // Enable to override BAUDRATE
+//#define SERIAL_PORT_2 2  // For ESP8266
+#define BAUDRATE_2 500000  // For ESP8266
 
 /**
  * Select a third serial port on the board to use for communication with the host.

Marlin/src/MarlinCore.cpp

@@ -1222,7 +1222,6 @@ void setup() {
   #endif
   #define SETUP_RUN(C) do{ SETUP_LOG(STRINGIFY(C)); C; }while(0)
 
-  MYSERIAL1.begin(BAUDRATE_2);  // PATCH: Knutwurst
   millis_t serial_connect_timeout = millis() + 1000UL;
   while (!MYSERIAL1.connected() && PENDING(millis(), serial_connect_timeout)) { /*nada*/ }