Merge branch 'mv88e6xxx-Watchdog-support'

Andrew Lunn says:

====================
mv88e6xxx Watchdog support

The Marvell switches have an in built watchdog over some of the
internal state machine. The watchdog can be configured to raise an
interrupt on error. The problem the watchdog found is then logged to
the kernel log.

The older switches can automagically perform a software reset when the
watchdog triggers. This just resets the internal state machine, but
leaves the switch configuration unchanged.

The 6390 family of switches cannot both raise an interrupt and
automagically perform a software reset. So the interrupt handler has
to perform the switch reset, and then re-enable the watchdog
interrupts.

This has been tested using hacked together debugfs code which allows
the "force" bit to be set, so cause a watchdog interrupt.

v2: Remove g2_prefix
====================

Signed-off-by: David S. Miller <davem@davemloft.net>