This is all you need (in a master file) to get pillar working with gitfs. Note that "pillar_roots" aren't used.

pillar_gitfs

fileserver_backend:
  - git

gitfs_remotes:
  - [email protected]:somerepogroup/salt-states.git

#####         Pillar settings        #####
##########################################
# Salt Pillars allow for the building of global data that can be made selectively
# available to different minions based on minion grain filtering. The Salt
# Pillar is laid out in the same fashion as the file server, with environments,
# a top file and sls files. However, pillar data does not need to be in the
# highstate format, and is generally just key/value pairs.

#pillar_roots:
#  base:
#    - /srv/pillar

ext_pillar:
    - git: master [email protected]:somerepogroup/pillar.git