nfc: pn544: mark ACPI and OF device ID tables as maybe unused

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

    drivers/nfc/pn544/i2c.c:53:36: warning:
        ‘pn544_hci_i2c_acpi_match’ defined but not used [-Wunused-const-variable=]
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210528124200.79655-9-krzysztof.kozlowski@canonical.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/nfc/pn544/i2c.c

@@ -50,7 +50,7 @@ static const struct i2c_device_id pn544_hci_i2c_id_table[] = {
 
 MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);
 
-static const struct acpi_device_id pn544_hci_i2c_acpi_match[] = {
+static const struct acpi_device_id pn544_hci_i2c_acpi_match[] __maybe_unused = {
 	{"NXP5440", 0},
 	{}
 };
@@ -951,7 +951,7 @@ static int pn544_hci_i2c_remove(struct i2c_client *client)
 	return 0;
 }
 
-static const struct of_device_id of_pn544_i2c_match[] = {
+static const struct of_device_id of_pn544_i2c_match[] __maybe_unused = {
 	{ .compatible = "nxp,pn544-i2c", },
 	{},
 };