netfilter:Changes to Allow IRC DCC

Existing IRC conntrack code does source address translation for
TCP handshake packets, when they are initiated from outside client.
Since the data transfer happens through Hardware Accelarator, source
translation will not happen and hence data transfer fails.

We can fix this by preventing source address translation
during handshake.

Change-Id: I613435a53ab58db51505afe057bfbec68259e277
Signed-off-by: Ravinder Konka <rkonka@codeaurora.org>