Update access-fms to point to the correct FMS branch

[aidanheerdegen]

The repo on which the access-fms repo depends has undergone a reorganisation

ACCESS-NRI/FMS#2

Once this is completed via ACCESS-NRI/FMS#4 the spack package needs to be updated to point to the correct branches.

[harshula]

The SPR currently contains:

    version("master", branch="master")
    # TODO: Needs to be changed once changes to build system enter master.
    version("development", branch="development", preferred=True)