max111x: put it into the 'misc' category

The category of the max111x device is not set, put it into the 'misc'
category.

Signed-off-by: Gan Qixin <ganqixin@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20201112125824.763182-5-ganqixin@huawei.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>