net/mlx5: Convert SF port_indices xarray to function_ids xarray

[ Upstream commit 2284a483 ]

No need to lookup for sf by a port index. Convert the xarray to have
function id as an index and optimize the remaining function id
based lookup.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Stable-dep-of: 26e42ec7 ("net/mlx5: Nack sync reset when SFs are present")
Signed-off-by: Sasha Levin <sashal@kernel.org>