This driver adds initial support for several devices from Siemens. It is
based on a platform driver introduced in an earlier commit.

One of the supported machines does access a GPIO pin to enable the
watchdog. Here we poke GPIO memory because pinctrl does not come up.
Signed-off-by: Henning Schild <henning.schild@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20211213120502.20661-4-henning.schild@siemens.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>