devlink: Change devlink_reload_supported() param type

Change devlink_reload_supported() function to get devlink_ops pointer
param instead of devlink pointer param.
This change will be used in the next patch to check if devlink reload is
supported before devlink instance is allocated.

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>