gst-ptp-helper permissions could be better on Solaris

gst-ptp-helper needs to listen on ports < 1024, so it needs extra powers. On Linux this is done either by suid-ing the binary or with a more fine-grained approach by using capabilities. Solaris doesn't have Linux capabilities and having this binary suid would be a too high a risk. Over here we use privileges to achieve the same goal as capabilities.solaris-gstreamer.patch (See https://blogs.oracle.com/solaris/when-setuid-root-no-longer-means-setuid-root-forced-privileges-v2 or https://docs.oracle.com/cd/E37838_01/html/E61023/prbac-2.html)

The attached patch adds support for Solaris privileges.

To complete the change the attached file library_desktop_gstreamer-1 needs to be installed in /etc/security/exec_attr.d/ (I wasn't sure how to do that in your workspace)