Add the operations that allow wlcore to trigger commands to the
firmware and acknowledge when an event has been fully received.

Allocate a private buffer to hold the maximum sized cmd. Send the
entire length of the buffer each time a command is sent to signal
EOT. Remove the previous EOT mechanism.
Signed-off-by: NLuciano Coelho <coelho@ti.com>
Signed-off-by: NArik Nemtsov <arik@wizery.com>