staging: line6: drop amp/effects dump request triggers

Since the driver no longer needs to keep state of device parameters it
is no longer necessary to refresh state when messages that affect other
parameters are sent.  Drop the code to trigger a dump when amp/effects
are changed.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>