Add Panelolu2 pins for RAMPS1.3

Marlin/pins.h

@@ -485,6 +485,14 @@
         #define BTN_ENC 35
 
         #define SDCARDDETECT 49
+      #elif defined(LCD_I2C_PANELOLU2)
+        #define BTN_EN1 47  //reverse if the encoder turns the wrong way.
+        #define BTN_EN2 43
+        #define BTN_ENC 32
+        #define SDSS 53
+        #define SDCARDDETECT -1
+        #define KILL_PIN 41
+        #define FAN_PIN 45
       #else
         //arduino pin which triggers an piezzo beeper
         #define BEEPER 33  // Beeper on AUX-4