MAINTAINERS: nfc: include linux-nfc mailing list

Keep all NFC related patches in existing linux-nfc@lists.01.org mailing
list.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>