i40e: Fix LED blinking flow for X710T*L devices

Add X710T*L device specific operations (in port LED detection and
handling of GLGEN_GPIO_CTL.PIN_FUNC field) to enable LED blinking.

Signed-off-by: Damian Milosek <damian.milosek@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>