doc: Fix ASCII diagram in topology.md
doc: Fix ASCII diagram in topology.md

I've messed up a few places in the diagram in the last conversion.
This one is taken from the original.rst and is untabified.

Signed-off-by: Yasushi SHOJI <afa9ca3be149447780c2f7b524d61ed3d3db63f9@spacecubics.com>

libcsp/libcsp,libcsp/libcsp