xfs: report projid32bit feature in geometry call

When xfs gained the projid32bit feature, it was never added to
the FSGEOMETRY ioctl feature flags, so it's not queryable without
this patch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>