platform_data/mlxreg: Extend core platform structure

Add 'capability' field to structure 'mlxreg_core_platform_data'.
The purpose of this filed to indicate  the actual number of the
components within the particular group. Such components could be,
for example the number of the FAN drawers. Some systems are equipped
with FAN drawers with one tachometer inside, others with FAN drawers
with several tachometers inside.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200923172053.26296-5-vadimp@nvidia.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>