NFC: Send netlink events for secure elements additions and removals

When an NFC driver or host controller stack discovers a secure element,
it will call nfc_add_se(). In order for userspace applications to use
these secure elements, a netlink event will then be sent with the SE
index and its type. With that information userspace applications can
decide wether or not to enable SEs, through their indexes.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>