msm: camera2: cpp: Reduce debug prints in cpp driver

The cpp driver had prints to monitor the status when node
is closed. This change makes them as pr_debug messages.

Change-Id: I8a78e6b38d7a702ed38f980d8fa658f50439da0f
Signed-off-by: Rajakumar Govindaram <rajakuma@codeaurora.org>