msm: camera: isp: Reuse existing release function

When calling release in activated state, we need to do 2 steps,
stop the devices and then release. There are existing APIs for
both, so reuse them to avoid missing any fixes made in one and
accidentally skipped in other causing bugs.

Change-Id: I258b881ed358456e5c8e35968fe9970dbc4ea940
Signed-off-by: Harsh Shah <harshs@codeaurora.org>