qemu: cleanup unused macros in cirrus

Cirrus vga has a copy of many PCI macros,
and it doesn't even use them. Clean up.
We also don't need to override header type
as it is NORMAL by default.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>