net/mlx4: adjust initial value of vl_cap in mlx4_SET_PORT

net/mlx4: adjust initial value of vl_cap in mlx4_SET_PORT

Adjust the initial value of vl_cap in mlx4_SET_PORT such that
only for CX3 devices we start with 8 VLs, in an attempt to
avoid errors such as:

 mlx4_core 0000:06:00.0: command 0xc failed: fw status = 0x40
 mlx4_core 0000:06:00.0: vhcr command:0xc slave:0 failed with error:0, status -12

to appear in the system log.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>
(Ported from Mellanox OFED 2.4)

Signed-off-by: Mukesh Kacker <mukesh.kacker@oracle.com>