diag: dci: Add dci channel information to debugfs

Diag uses two smd channels for dci data - one for req/rsp and the
other for logs and events. This patch adds channel information
while recording data received from these channels.

Change-Id: If07ce047fed444696259d201bef18f769d98b83a
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>