QNX: Add QQnxEglWindow::format() overload

QQnxEglWindow should return correct QSurfaceFormat.

Task-number: QTBUG-64306
Change-Id: I3ba2a9d84f39af66c3b8f58ae3e26edc695f5612
Reviewed-by: James McDonnell <jmcdonnell@blackberry.com>

src/plugins/platforms/qnx/qqnxeglwindow.h

@@ -60,6 +60,8 @@ public:
 
     void setGeometry(const QRect &rect) override;
 
+    QSurfaceFormat format() const override { return m_format; }
+
 protected:
     int pixelFormat() const override;
     void resetBuffers() override;