MAINTAINERS: nfc: s3fwrn5: Drop Krzysztof Opasiak

Emails to Krzysztof Opasiak bounce ("Recipient address rejected: User
unknown") so drop his email from maintainers of s3fwrn5 NFC bindings and
driver.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>