NFC: Sony Port-100 Series driver

This adds support for the Sony NFC USB dongle RC-S380, based on the
Port-100 chip. This dongle is an analog frontend and does not implement
the digital layer. This driver uses the nfc_digital module which is an
implementation of the NFC Digital Protocol stack.

This patch is a skeleton. It only registers the dongle against the NFC
digital protocol stack. All NFC digital operation functions are stubbed
out.

Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Cc: Stephen Tiedemann <stephen.tiedemann@gmail.com>
Tested-by: Cho, Yu-Chen <acho@suse.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>