add(board): Add M5Stack NanoC6 Dev Kit

Author: lboue

variants/m5stack_stickc_plus/m5stack_nanoc6/pins_arduino.h

@@ -20,6 +20,11 @@ static const uint8_t RX = 17;
 static const uint8_t SDA = 2;
 static const uint8_t SCL = 1;
 
+static const uint8_t SS = 21;
+static const uint8_t MOSI = 18;
+static const uint8_t MISO = 20;
+static const uint8_t SCK = 19;
+
 static const uint8_t A1 = 1;
 static const uint8_t A2 = 2;
 static const uint8_t A3 = 2;