Another EDMA interface update.  Fixes documentation for the linking
calls to be kerneldoc style.  Rename parameters so they're meaningful
(from/to vs lch/lch_que) and unsigned (eliminates some error checks).
Remove unused edma_unlink() parameter.  Move this code so it's grouped
with the other calls which only modify parameter RAM.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>