drivers: mailbox: Write data to the controller without sending

In addition to the requests that have to be sent to the remote processor
through the mailbox controller, there may be data, that may need to be
sent to the controller, but not the remote processor, atleast right
away. Such data need not be buffered by the mailbox framework. Since
data is also not sent to the remote processor immediately,
acknowlegement will not be expected by the mailbox framework.

Change-Id: I6b6e81f593af0ed1cadde269624ebfa2a1591f5b
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
3 files changed