New port: sysutils/mac_rtprio

Simple MAC framework policy to manage access for setting realtime priorities by
selected GID.Running kldload mac_rtprio.ko to load the kernel module. The load
action require root permissions. Set GID that should be able to change realtime
priorities:

sysctl security.mac.rtprio.gid=1001

and enable enforcing:

sysctl security.mac.rtprio.enabled=1

WWW: https://github.com/pbiernacki/mac_rtprio

PR: 219377
Submitted by: amutu@amutu.com
Reviewed by: bapt