ixgbe: always call setup_mac_link for multispeed fiber

Remove the logic which would previously skip the link configuration
in the case where we are already at the requested speed in
ixgbe_setup_mac_link_multispeed_fiber().

By exiting early we are skipping the link configuration and as such
the driver may not always configure the PHY correctly for SFP+.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>