iwlwifi: using PCI_DEVICE macro

PCI_DEVICE macro is more concise when using defualt values
in device definitions

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>