raspberrypi-userland conflicts with mesa-libs

[adr]

> Tracked in bug 225053. After r495793 at least multimedia/omxplayer
> builds fine[1] on the package cluster.

It is not about building omxplayer. It is about raspberrypi-userland
been installed in LOCALBASE, conflicting with libEGL from mesa, so you
can not install any port using raspberrypi-userland along with mesa-libs.

I'm been using FreeBSD just for a few days. I don't think I'm the appropiate
person to choose a new prefix for a port.