Added QFN20 package check for status LEDs GPIO configs in `ext/badge/cp2102.c`

[BB-301]

As visible from Figure 5.3 and Table 5.3 in the CP210N Datasheet, the QFN20 package uses GPIO.2/TXT and GPIO.3/RXT, as opposed to GPIO.0/TXT and GPIO.1/RXT, respectively, for the other two packages (i.e., QFN28 and QFN24). So here (i.e., in ext/badge/cp2102.c, in the GPIO-related "if" block) we need to check whether we are dealing with QFN20, and, if so, adjust the target bits accordingly.