gst1-plugins-good: add package license file to Makefile

Signed-off-by: W. Michael Petullo <mike@flyn.org>

multimedia/gst1-plugins-good/Makefile

@@ -11,6 +11,7 @@ PKG_VERSION:=1.0.7
 PKG_RELEASE:=1
 PKG_MAINTAINER:=W. Michael Petullo <mike@flyn.org>
 PKG_LICENSE:=LGPLv2
+PKG_LICENSE_FILE:=COPYING
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/gst-plugins-good-$(PKG_VERSION)
 PKG_SOURCE:=gst-plugins-good-$(PKG_VERSION).tar.xz