cpu/samd21: fix or add missing EXTI on GPIO

Signed-off-by: dylad <dylan.laduranty@mesotic.com>

cpu/samd21/periph/gpio.c

@@ -41,10 +41,10 @@
  * @brief   Mapping of pins to EXTI lines, -1 means not EXTI possible
  */
 static const int8_t exti_config[2][32] = {
-    {-1,  1, -1, -1,  4,  5,  6,  7, -1,  9, 10, 11, 12, 13, 14, 15,
-     -1,  1,  2,  3, -1, -1,  6,  7, 12, 13, -1, 15,  8, -1, 10, 11},
-    { 0, -1,  2,  3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-      0,  1, -1, -1, -1, -1,  6,  7, -1, -1, -1, -1,  8, -1, -1, -1},
+    { 0,  1,  2,  3,  4,  5,  6,  7, -1,  9, 10, 11, 12, 13, 14, 15,
+      0,  1,  2,  3,  4,  5,  6,  7, 12, 13, -1, 15,  8, -1, 10, 11},
+    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+      0,  1, -1, -1, -1, -1,  6,  7, -1, -1, -1, -1, -1, -1, 14, 15},
 };
 
 /**