BGQ - Remove ability to make a sub-block with a geometry with one or more

of it's dimensions of length 3.  There is a limitation in the IBM I/O
subsystem that is problematic with multiple sub-blocks with a dimension
of length 3, so we will disallow them to be able to be created.  This
mean you if you ask the system for an allocation of 12 c-nodes you will
be given 16.  If this is ever fix in BGQ you can remove this patch.