nfc: mrvl: mark OF device ID tables as maybe unused

The driver can match either via OF or I2C ID tables.  If OF is disabled,
the table will be unused:

    drivers/nfc/nfcmrvl/spi.c:199:34: warning:
        ‘of_nfcmrvl_spi_match’ defined but not used [-Wunused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210528124200.79655-5-krzysztof.kozlowski@canonical.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>