diag: Remove hdlc status dependeny on session_info

The patch removes the hdlc status dependency on session_info
protected by md_session_lock inserting delay in processing data
off peripheral.

CRs-Fixed: 2193991
Change-Id: Ia79c0efe82803c15ccae42b00d95258f52242eee
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>