platform/x86: mlx-platform: Add mlx-wdt platform driver activation

platform/x86: mlx-platform: Add mlx-wdt platform driver activation

Add mlx-wdt platform driver activation. Watchdog driver uses the same
regmap infrastructure as others Mellanox platform drivers. Specific
registers description for watchdog platform data configuration are
added to mlx-platform. There are the registers for watchdog timer
manipulation, and action setting on watchdog timer expiration.
The watchdog action function could be configured to perform one of the
following: system reset, setting PWM to full speed or counter
increment.
Two types of watchdog devices are supported main and auxiliary.
These devices are co-exist and each of them could be configured to
handle the specific action.

Signed-off-by: Michael Shych <michealsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>