Add RTEMS notes.

documentation/RELEASE_NOTES.html

@@ -59,6 +59,7 @@ if the dbBkpt facility is used.</p>
 <p>I/O redirection from vxWorks startup scripts now works.</p>
 
 <h4>RTEMS</h4>
+<p>Added support for setting NFS server/mount information from PPCBUG argument strings.</p>
 <p>rtems_shutdown_executive is now called on IOC exit.  On many  BSPs this will return control to the bootstrap PROM.</p>
 <p>Set POSIX TZ environment variable from NVRAM, or failing that, from EPICS_TIMEZONE.</p>
 <p>Cleaned up support for obtaining network configuration from NVRAM.</p>