NFC: hci: Change nfc_hci_send_response gate parameter to pipe

As there can be several pipes connected to the same gate, we need
to know which pipe ID to use when sending an HCI response. A gate
ID is not enough.

Instead of changing the nfc_hci_send_response() API to something
not aligned with the rest of the HCI API, we call nfc_hci_hcp_message_tx
directly.

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