Loose the linked list for params and use xarray instead.

Note that this is required to be eventually possible to call
devl_param_driverinit_value_get() without holding instance lock.
Signed-off-by: NJiri Pirko <jiri@nvidia.com>
Reviewed-by: NSimon Horman <simon.horman@corigine.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>