[CI] Add virtio in CI builds

Author: kbumsik

CI/build/conf/cores_config.json

@@ -11,6 +11,14 @@
         {
           "name": "STEVAL_MKSBOX1V1",
           "options": "usb=CDCgen"
+        },
+        {
+          "name": "STM32MP157A_DK1",
+          "options": "virtio=enabled"
+        },
+        {
+          "name": "STM32MP157C_DK2",
+          "options": "virtio=generic"
         }
       ],
       "sketches": [

CI/build/conf/cores_config_ci.json

@@ -11,6 +11,14 @@
         {
           "name": "STEVAL_MKSBOX1V1",
           "options": "usb=CDCgen"
+        },
+        {
+          "name": "STM32MP157A_DK1",
+          "options": "virtio=enabled"
+        },
+        {
+          "name": "STM32MP157C_DK2",
+          "options": "virtio=generic"
         }
       ],
       "sketches": [

CI/build/conf/cores_config_travis.json

@@ -7,6 +7,14 @@
         {
           "name": "NUCLEO_L031K6",
           "options": "opt=oslto"
+        },
+        {
+          "name": "STM32MP157A_DK1",
+          "options": "virtio=enabled"
+        },
+        {
+          "name": "STM32MP157C_DK2",
+          "options": "virtio=generic"
         }
       ],
       "sketches": [

CI/build/examples/BareMinimum/BareMinimum.ino

@@ -42,7 +42,8 @@ SoftwareSerial swSerial(10, 11);
 
 void setup() {
   // Serial HW & SW
-#if !defined(USBD_USE_CDC) && !defined(DISABLE_GENERIC_SERIALUSB)
+#if (!defined(USBD_USE_CDC) && !defined(DISABLE_GENERIC_SERIALUSB)) &&\
+    (!defined(VIRTIOCON) && !defined(DISABLE_GENERIC_SERIALVIRTIO))
   Serial.setRx(PIN_SERIAL_RX);
   Serial.setTx(digitalPinToPinName(PIN_SERIAL_TX));
 #endif