mlx4_core: Clean up enabling of SENSE_PORT for older (ConnectX-1/-2) HCAs

Instead of having a hard-coded "PCI device ID != 0x1003" (which
obviously breaks as newer devices with ID != 0x1003 become available),
instead let's set a flag in our PCI device table for the older devices
where we're supposed to force using SENSE_PORT.  This also avoids
enabling SENSE_PORT for virtual functions by mistake.

Signed-off-by: Roland Dreier <roland@purestorage.com>