QCamera2: use cam_lock when camera open

In dual Camera use case, when one camera opened and in preview status,
if second camera enter into open operation, in current code,
camera_open() will hold g_intf_lock until open finished. So during
second open, the operation needed by first camera will be blocked
when try to get g_intf_lock (example is preview frame bufDone).

So we need use cam_lock instead when opening, and not block other
camera obj's operation.

Change-Id: Ie6e4202be64735ce24a5a35b02be7eaf22c5d69d
2 files changed