cec: Fix message parsing and enable wakeup feature

- Fix the message parsing in the HAL by adjusting the offset for
  the message size coming from the driver.
- Enable the CEC wakeup feature to allow CEC commands to suspend
  and resume the device from HDMI TV.

CRs-Fixed: 814136
Change-Id: I9514c34dad95073ea694b9caf95dfba62c890f3e
1 file changed