hwmon: (gpio-fan) drop of_match_ptr for ID table

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 <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230312193723.478032-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>