[release/2.x] fix(uart): Set back Pin signal polarity

[SuGlider]

Description of Change

Backport to release/v2.x branch

Fixes a problem related to inverting signal polarity back to normal after a previous inversion.
This shall set the correct polarity in Serial.begin().

Tests scenarios

#include <Arduino.h>
#include <HardwareSerial.h>

HardwareSerial serial(0);   // use serial(1) for comparison

void setup() {}

void loop() {
  serial.begin(115200, SERIAL_8N1, 3, 1, false);
  serial.write("hello");
  serial.flush();
  serial.end();

  serial.begin(115200, SERIAL_8N1, 3, 1, true);
  serial.write("hello");
  serial.flush();
  serial.end();
}

Related links

Fix #9896

[mha1]

while you're at it, can you please remove this comment in both PRs:
// Is it right or the idea is to swap rx and tx pins?

[mha1]

thanks

[P-R-O-C-H-Y]

@SuGlider PTAL.