soc: qcom: glink_probe: Add SSR support for GLINK

RPMSG GLINK should be registered and unregisted as the remote processor
comes up and down. During probe time, register a notifier block for each
subsystem specified in device tree.

The GLINK_SSR channel is part of the SSR handling for the GLINK RPMSG
framework. Register as a rpmsg driver for the GLINK SSR driver and send
the required SSR notifications to interested subsystems.

The GLINK subsystem names differ from the PIL image names. Add a device
tree property to keep track of the GLINK name and the PIL names.

Change-Id: Ic6d5130a1f15776e51ba6698c7d09d561d9f967f
Signed-off-by: Chris Lew <clew@codeaurora.org>