Implement 2D graphic API (#87)

* Implement 2D graphic library based on LittlevGL

* Add lvgl license file

samples/simple/CMakeLists.txt.in

@@ -0,0 +1,41 @@
+# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required(VERSION 2.8.2)
+
+project(lvgl_download NONE)
+
+include(ExternalProject)
+
+ExternalProject_Add(${lv_name}
+    GIT_REPOSITORY https://github.com/littlevgl/lvgl.git
+    GIT_TAG        ""
+    BINARY_DIR     ""
+    SOURCE_DIR            "${LVGL_DIR}"
+    CONFIGURE_COMMAND     ""
+    BUILD_COMMAND         ""
+    INSTALL_COMMAND       ""
+    TEST_COMMAND          ""
+  )
+
+ExternalProject_Add(${lv_drivers_name}
+    GIT_REPOSITORY https://github.com/littlevgl/lv_drivers.git
+    GIT_TAG        ""
+    BINARY_DIR     ""
+    SOURCE_DIR            "${LV_DRIVERS_DIR}"
+    CONFIGURE_COMMAND     ""
+    BUILD_COMMAND         ""
+    INSTALL_COMMAND       ""
+    TEST_COMMAND          ""
+  )