net: aquantia: fix undefined devm_hwmon_device_register_with_info reference

drivers/net/ethernet/aquantia/atlantic/aq_drvinfo.o: In function `aq_drvinfo_init':
aq_drvinfo.c:(.text+0xe8): undefined reference to `devm_hwmon_device_register_with_info'

Fix it by using #if IS_REACHABLE(CONFIG_HWMON).

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>