package/qt5/qt5webview: install missing plugins

Fixes:
  No WebView plug-in found!

Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/qt5/qt5webview/qt5webview.mk

@@ -43,6 +43,7 @@ endif
 ifneq ($(BR2_STATIC_LIBS),y)
 define QT5WEBVIEW_INSTALL_TARGET_LIBS
 	cp -dpf $(STAGING_DIR)/usr/lib/libQt5WebView.so.* $(TARGET_DIR)/usr/lib
+	cp -dpfr $(STAGING_DIR)/usr/lib/qt/plugins/webview $(TARGET_DIR)/usr/lib/qt/plugins
 endef
 endif