soc: qcom: glink: Add list of available logical Channel IDs

When a channel is closed, add the channel's id to a list of available
channel IDs. When a channel is opened, the channel ID can be used from
that list.

Change-Id: I78ec85b1d21fc1c92ac4d159d8f8c2b1c31c3183
Signed-off-by: Atish Kumar Patra <apatra@codeaurora.org>
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>