hwmon: (gpio-fan) drop of_match_ptr for 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 might not be relevant here). This
also fixes !CONFIG_OF error:

drivers/hwmon/gpio-fan.c:484:34: error: ‘of_gpio_fan_match’ defined but not used [-Werror=unused-const-variable=]

Note(groeck): The build error is only seen if Kconfig dependencies
are messed up. The driver depends on OF_GPIO which should depend
on OF. This was temporarily broken in linux-next, and it was
possible to select CONFIG_OF=n and CONFIG_SENSORS_GPIO_FAN=y.
Nevertheless, this is a sensible fix.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/gpio-fan.c

···
 	.driver	= {
 		.name	= "gpio-fan",
 		.pm	= pm_sleep_ptr(&gpio_fan_pm),
-		.of_match_table = of_match_ptr(of_gpio_fan_match),
+		.of_match_table = of_gpio_fan_match,
 	},
 };