platform_data/mlxreg: support new watchdog type with longer timeout period

Add new watchdog type 3 with longer timeout period.
Extend size of health_cntr field that that can be used to init watchdog
timeout period.

Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Reviewed-by: Vadim Pasternak <vadimp@mellanox.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200504141427.17685-2-michaelsh@mellanox.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>