Merge pull request #8305 from aabadie/pr/boards/microbit_saul_gpio

boards/microbit: use gpio inverted flag for buttons

boards/microbit/include/gpio_params.h

@@ -35,12 +35,14 @@ static const saul_gpio_params_t saul_gpio_params[] =
     {
         .name = "Button A",
         .pin  = BTN0_PIN,
-        .mode = BTN0_MODE
+        .mode = BTN0_MODE,
+        .flags = SAUL_GPIO_INVERTED,
     },
     {
         .name = "Button B",
         .pin  = BTN1_PIN,
-        .mode = BTN1_MODE
+        .mode = BTN1_MODE,
+        .flags = SAUL_GPIO_INVERTED,
     },
 };