x11/nvidia-secondary-driver[-390]: Remove dead port

[kbowling]

Summary

The requisite nvidia-hybrid-graphics port was removed in
9b8dd11af61165b9e0291140d0f8890651a6def5

libglvnd should make the need to manually move libraries around
unnecessary and has been mandatory for a long time since
5343f55d875779eca78236446cd19d67f58c4bce

[junchoon_dec.sakura.ne.jp]

Related discussions at Bug 285803, starting from comment 7.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=285803#c7

Not actually about deletions itself, though, discussing about the background.