Fixed handling of Ax constants on Leonardo

Fixed mistake in assignment and handling of A6-A11 constants.  Renumbered constants for all Ax channels.

Author: zeveland

hardware/arduino/cores/arduino/wiring_analog.c

@@ -43,6 +43,8 @@ int analogRead(uint8_t pin)
 
 #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
 	if (pin >= 54) pin -= 54; // allow for channel or pin numbers
+#elif defined(__AVR_ATmega32U4__)
+	if (pin >= 18) pin -= 18; // allow for channel or pin numbers
 #else
 	if (pin >= 14) pin -= 14; // allow for channel or pin numbers
 #endif