NFC: nci: Support logical connections management

In order to communicate with an NFCEE, we need to open a logical
connection to it, by sending the NCI_OP_CORE_CONN_CREATE_CMD
command to the NFCC. It's left up to the drivers to decide when
to close an already opened logical connection.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>