vxge: Allow driver load for all enumerated pci functions.

- Allow all instances of the driver be loaded when multiple pci functions are
enumerated. The max_config_dev driver loadable option limits the driver
load instances if required. The X3100's function configuration of single/multi
function, SR and MR IOV allows the user to select the number of pci functions.
 
Signed-off-by: Sreenivasa Honnur <sreenivasa.honnur@exar.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@exar.com>
Signed-off-by: David S. Miller <davem@davemloft.net>