hwmon: (sch56xx) Add support for the integrated watchdog (v2)

Add support for the watchdog integrated into the SMSC SCH5627 and
SCH5636 superio-s. Since the watchdog is part of the hwmon logical device
and thus shares ioports with it, the watchdog driver is integrated into the
existing hwmon drivers for these.

Note that this version of the watchdog support for sch56xx superio-s
implements the watchdog chardev interface itself, rather then relying on
the recently added watchdog core / watchdog_dev. This is done because
currently some needed functionality is missing from watchdog_dev, as soon
as this functionality is added (which is being discussed on the
linux-watchdog mailinglist), I'll convert this driver over to using
watchdog_dev.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[guenter.roeck@ericsson.com: Added missing linux/slab.h include]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/Documentation/hwmon/sch5636 b/Documentation/hwmon/sch5636
index f83bd1c..7b0a01d 100644
--- a/Documentation/hwmon/sch5636
+++ b/Documentation/hwmon/sch5636
@@ -26,6 +26,9 @@
 temperature sensors are actually implemented on the motherboard, so you will
 likely see fewer temperature and fan inputs.
 
+The Fujitsu Theseus hwmon solution also contains an integrated watchdog.
+This watchdog is fully supported by the sch5636 driver.
+
 An application note describing the Theseus' registers, as well as an
 application note describing the protocol for communicating with the
 microcontroller is available upon request. Please mail me if you want a copy.