diag: dci: Remote DCI channel discovery support

Diag driver on Apps opens the remote DCI channels on remote ASICs
irrespective of the remote side support. Add a handshaking
mechanism that closes the DCI channel if handshaking fails.

Change-Id: I92bb0c6f2c8363bc3fd45d3c60bd9e79e7a216f0
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>