igc: Remove phy->type checking

i225 devices have only one phy->type: copper. There is no point checking
phy->type during the igc_has_link method from the watchdog that
invoked every 2 seconds.
This patch comes to clean up these pointless checkings.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>