ixgbe: include QSFP PHY types in ixgbe_is_sfp()

This patch makes sure that QSFP+ modules use the SFP+ code path for
setting up link.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>