dynamic hypertransport links

[Stefan Reinauer]

In the progress of getting hypertransport setup completely dynamic, I
made the following patch that completely gets rid of the CONNECTION
and link name macros in coherent_ht.c
(UP, ACROSS, DOWN and CONNECTION_0_1, CONNECTION_0_2, CONNECTION_1_3)
Therefore I added two simple helper functions that gain the needed
information from generate_row().
This patch probably raises the register pressure during ht setup, but
even on a 4p machine I could not see any problems with romcc. 
Dropping another couple of hardcodes seems like the right thing to
do[tm].

If nobody is opposing, I am going to check this into CVS.

Stefan