gstreamer1: add package license to Makefile

Signed-off-by: W. Michael Petullo <mike@flyn.org>
gst1-plugins-bad: add package license to Makefile

Signed-off-by: W. Michael Petullo <mike@flyn.org>
gst1-plugins-base: add package license to Makefile

Signed-off-by: W. Michael Petullo <mike@flyn.org>
gst1-plugins-good: add package license to Makefile

Signed-off-by: W. Michael Petullo <mike@flyn.org>
gst1-plugins-ugly: add package license to Makefile

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