mlxsw: spectrum: Don't use resource ID of 0

In commit 14530746 ("devlink: Remove top_hierarchy arg to
devlink_resource_register"), the "top_hierarchy" parameter to
devlink_resource_register() was removed in favor of using the parameter
"parent_resource_id" exclusively to determine who the parent is. The
root node's resource ID for this purpose is
DEVLINK_RESOURCE_ID_PARENT_TOP with the value 0. It is therefore
problematic that the resource MLXSW_SP_RESOURCE_KVD has also ID of 0.

Fix this by numbering driver-specific resources from 1.

Fixes: 14530746

 ("devlink: Remove top_hierarchy arg to devlink_resource_register")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>