ixgbe: X540 thermal warning interrupt not a GPI

The X540 thermal interrupt (IXGBE_EIMS_TS) is not an SDP, so it
doesn't need to be enabled in ixgbe_setup_gpie(). In fact the
value is simply not for the GPIE register at all.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>