ixgbe: Allow the VF driver to be loaded before the PF driver

The PF Reset Done bit should not be set in the extended control register
until the PF has actually completed the bring up process.  It is a mis-
interpretation of the purpose of this bit to assume it should be set
when the physical reset of the device is done.  Instead it should be used
to indicate to the VFs when the PF is ready to provide them with required
services.  This is not until after the PF is finished coming up and ready
to process mailbox events.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>