staging: nvec: add ability to ignore EC responses in sync writes

In case we just want to submit a message to the EC but are not
interested in its response, we can free the response buffer early.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Link: https://lore.kernel.org/r/20240406123123.37148-2-marvin24@gmx.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>