platform/x86: mlx-platform: Make activation of some drivers conditional

platform/x86: mlx-platform: Make activation of some drivers conditional

Current assumption in driver that any system is capable of LED,
hotplug or watchdog support. It could be not true for some new coming
systems.
Add validation for LED, hotplug, watchdog configuration and skip
activation of relevant drivers if not configured.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Oleksandr Shamray <oleksandrs@nvidia.com>
Link: https://lore.kernel.org/r/20220711084559.62447-2-vadimp@nvidia.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>