pci: initialize pci config headers depending it pci header type.

- Only sets default subsystem id for header type 00.(normal header type)
  because header type 01 doesn't have subsystem id, and uses the register
  for other purpose. So setting default subsystem id doesn't make sense.

- initialize wmask more for header type 01.(bridge header type)
  Without those wmasks, linux was confused not boot,
  and lspci was confused not to print out expected IO/memory range.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
