msm: subsystem_restart: Send sysmon event notifications to all subsystems

Currently, sysmon notifications are send to only subsystems which
call sysmon_send_event explicity. This leads to multiplication of
code every time that a subsystem needs these notifications.

Instead, notifications are sent to all the registered subsystems.
What the subsystems do with the information is left upto them.

Change-Id: I6396b77a36a08993eed0ad6fc1bfc7cf8b4efc09
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>