This patch primarily renames functions to use an edma_ prefix and remove
a needless infix "_dma_" token ... except that "src_params" became "src",
and "dest_params" became "dest".  Parameters which identify parameter RAM
slots were renamed as "slot" from "lch".

Also, the slot numbers become unsigned (supporting a minor code shrink),
and a handful of needless temporary variables were removed.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>