net/mlx5: E-Switch, Get reg_c1 value on miss

The HW model implicitly decapsulates tunnels on chain 0 and sets reg_c1
with the mapped tunnel id. On miss, the packet does not have the outer
header and the driver restores the tunnel information from the tunnel id.

Getting reg_c1 value in software requires enabling reg_c1 loopback and
copying reg_c1 to reg_b. reg_b comes up on CQE as cqe->imm_inval_pkey.

Use the reg_c0 restoration rules to also copy reg_c1 to reg_B.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>