msm: camera: mem_mgr: release buffers after usage

Call cam_mem_put_cpu_buf corresponding to
cam_mem_get_cpu_buf calls to make sure ref_cnt
is balanced and buffer is freed when all
clients are done with the buffer usage.

CRs-Fixed: 3547081
Change-Id: I9414829d6f17c368f2718fe05dbe25c71b31e674
Signed-off-by: Nirmal Abraham <quic_c_nabrah@quicinc.com>