nfc: MAINTAINERS: add Bug entry

Add a Bug section, indicating preferred mailing method for bug reports,
to NFC Subsystem entry.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -13820,6 +13820,7 @@ M:	Krzysztof Kozlowski <krzk@kernel.org>
 L:	linux-nfc@lists.01.org (subscribers-only)
 L:	netdev@vger.kernel.org
 S:	Maintained
+B:	mailto:linux-nfc@lists.01.org
 F:	Documentation/devicetree/bindings/net/nfc/
 F:	drivers/nfc/
 F:	include/linux/platform_data/nfcmrvl.h