char: msm_smd_pkt: check and remove the wakeup source during device close

Client closing the device immediately after receiving data leaves
the packet arrival wakeup source in active state and block the system
infinitely from entering into suspend state.

Check the state of wakeup source during close operation and release
if it is active.

CRs-Fixed: 989126
Change-Id: I2b7b85425a92afd4ad1f48e3699a0b81177976e5
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>