bnxt_en: Add new VF resource allocation strategy mode.

The new mode is "minimal-static" to be used when resources are more
limited to support a large number of VFs, for example  The PF driver
will provision guaranteed minimum resources of 0.  Each VF has no
guranteed resources until it tries to reserve resources during device
open.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>