esoc: Add mdm error-fatal notifier hook

Add an error-fatal notifier hook to the list of other client hooks,
which would notify the clients about modem's unexpected reset or
error-fatal.

Change-Id: I185c4b05795b7ffb0768c240f25cc487f3d67b63
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>