qt_test: add qt test example package

Signed-off-by: Andy Hu <andy.hu@starfivetech.com>

package/starfive/qt_test/src/mainwindow.cpp

@@ -0,0 +1,21 @@
+#include "mainwindow.h"
+#include "ui_mainwindow.h"
+#include <QMessageBox>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+    , ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+}
+
+MainWindow::~MainWindow()
+{
+    delete ui;
+}
+
+void MainWindow::on_pushButton1_clicked()
+{
+    QMessageBox::information(this , "information" , "Welcome to Riscv World!",
+                QMessageBox::Ok|QMessageBox::Default );
+}