Provide new rtems_bsdnet_rtrequest()

Delete superfluous code.

freebsd-to-rtems.py

@@ -692,9 +692,9 @@ rtems.addRTEMSSourceFiles(
 		'rtems/rtems-bsd-sysctlnametomib.c',
 		'rtems/rtems-bsd-thread.c',
 		'rtems/rtems-bsd-timesupport.c',
+		'rtems/rtems-bsdnet-rtrequest.c',
 		'rtems/rtems-kvm.c',
 		'rtems/rtems_mii_ioctl_kern.c',
-		'rtems/rtems-net-setup.c',
 		'rtems/rtems-syslog-initialize.c',
 		'rtems/syslog.c',
 		'ftpd/ftpd.c',