platform/mellanox: mlxreg-io: Extend number of hwmon attributes

Extend maximum number of the attributes, exposed to 'sysfs'.
It is requires in order to support modular systems, which
provide more attributes for system control, statuses and info.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Michael Shych <michaelsh@nvidia.com>
Link: https://lore.kernel.org/r/20211002093238.3771419-6-vadimp@nvidia.com


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