wdt: allow sun7i build

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Enable the internal thermal monitoring support of AXP20X chips

Hello

The previous patch never detect the enabling of thermal monitoring, this one solve this problem.
Sorry for the resent.

Bests regards

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>