iwlwifi: replace 0x8086 with PCI_VENDOR_ID_INTEL

Replace 0x8086 with PCI_VENDOR_ID_INTEL for PCI_DEVICE declaration.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>