mlxsw: pci: Add resources query implementation.

Add resources query implementation. If exists, query the HW for its
builtin resources instead of having them as consts in the code.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>