soc: qcom: glink: Increase SSR timeout, notify RPM in single-threaded mode

In some cases, delays in context switching can cause SSR notifications
to take a long time to send. This can cause responses from remote
processors to be received after the half-second timeout has expired. In the
case of RPM, the delay is further increased because the notification is
sent in the "request intent" mode, which queues a work item to send the
notification rather than sending it in the same context. If the RPM fails
to respond in time, a kernel panic is initiated.

Increase the SSR timeout to one second and send notifications to RPM in
single-threaded mode to ensure that responses can be received in time.

Change-Id: I987e3970c7bdf4e677f046cc7a3d39c8586871fa
Signed-off-by: Steven Cahail <scahail@codeaurora.org>