net/mlx4_core: Add basic elements for QCN

Add device capability, firmware command opcode and etc prior elements
needed for QCN suppprt. Disable SRIOV VF view/access for QCN is disabled.

While here, remove a redundant offset definition into the
QUERY_DEV_CAP mailbox.

Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/ethernet/mellanox/mlx4/cmd.c
Simple merge

diff --cc drivers/net/ethernet/mellanox/mlx4/fw.c
Simple merge

diff --cc include/linux/mlx4/cmd.h
Simple merge

diff --cc include/linux/mlx4/device.h
Simple merge