ixgbe: set device if before calling get_invariants

Fix an issue where set_phy_power was NULL for X550 copper devices
because get_invariants was called before hw->device_id was set.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>