diag: Close the SMD transport type if sockets are supported

Close the SMD control channel on receiving the feature mask
from peripheral on socket channel and if the sockets are supported.

Change-Id: I7b15b69741cfcc6763a6109f7fccfb2f68378584
Signed-off-by: Sreelakshmi Gownipalli <sgownipa@codeaurora.org>