soc: qcom: glink_probe: Move node parsing logic into helper

The complexity of adding a glink node may increase in the future for
SSR cases and new transports. Move this logic into a helper function
to avoid nested indentation.

Change-Id: I089975994023f0a8c5774f692e5affb488efcf01
Signed-off-by: Chris Lew <clew@codeaurora.org>