mfd: mt6397: Drop of_match_ptr from of_device_id table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it is not relevant here). This fixes
compile warning (!CONFIG_OF on x86_64):

drivers/mfd/mt6397-core.c:214:34: warning: ‘mt6397_of_match’ defined but not used [-Wunused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/mt6397-core.c

···
 	.probe = mt6397_probe,
 	.driver = {
 		.name = "mt6397",
-		.of_match_table = of_match_ptr(mt6397_of_match),
+		.of_match_table = mt6397_of_match,
 	},
 	.id_table = mt6397_id,
 };