remoteproc: qcom: Add per subsystem SSR notification

remoteproc: qcom: Add per subsystem SSR notification

Currently there is a single notification chain which is called whenever any
remoteproc shuts down. This leads to all the listeners being notified, and
is not an optimal design as kernel drivers might only be interested in
listening to notifications from a particular remoteproc. Create a global
list of remoteproc notification info data structures. This will hold the
name and notifier_list information for a particular remoteproc. The API
to register for notifications will use name argument to retrieve the
notification info data structure and the notifier block will be added to
that data structure's notification chain. Also move from blocking notifier
to srcu notifer based implementation to support dynamic notifier head
creation.

Reviewed-by: Alex Elder <elder@linaro.org>
Co-developed-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Link: https://lore.kernel.org/r/1592965408-16908-2-git-send-email-rishabhb@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>