You have 3 options:
(1) Try to trick your computer into running the binaries you have. You could do this by making a symbolic link from /usr/X11R6/lib/libXm.so.3 to the Motif libraries you DO have, and seeing if that will work.
(2) Compile AFNI and SUMA on your platform yourself. This is probably the best solution.
(3) Upgrade Linux on your computer to something compatible with what we have here.
bob cox