e1000: Allow NVM to setup LPLU for IGP2 and IGP3

Allow NVM to setup LPLU for IGP2 and IGP3. Only IGP needs LPLU D3
disabled during init here.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>