CEC: Make TV try to allocate logical address 0 first

HDMI Spec says TV shall try to allocate TV() logical address, unlike
other kinds of devices that are recommended to use the previously
allocated one.

Also included are small changes:

- reply with 'can not provide source' if TV has no source to provide
- return the present device info if we have one at the given path

Bug: 19045081
Change-Id: Icf17cb581f0ef2274e252ec5665f80bb1c08b494