mlxsw: spectrum_acl_tcam: Position vchunk in a vregion list properly

Vregion helpers to get min and max priority depend on the correct
ordering of vchunks in the vregion list. However, the current code
always adds new chunk to the end of the list, no matter what the
priority is. Fix this by finding the correct place in the list and put
vchunk there.

Fixes: 22a67766

 ("mlxsw: spectrum: Introduce ACL core with simple TCAM implementation")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>