Remove the setgid bit from the tga device (?).
Synchronize mode with modes used for related frame buffer devices
in MAKEDEV (tga doesn't appear in MAKEDEV).
Submitted by: kris
us a lot on older Alphas.
Andrew Gallatin, Thomas V. Crimi, and Peter Jeremy contributed to this
work along with the submitter.
Submitted by: Andrew M. Miklic <miklic@home.com>