pci: fix pci bridge fw path

qemu uses "pci" as name for pci bridges in the firmware device path.
seabios expects "pci-bridge".  Result is that bootorder is broken for
devices behind pci bridges.

Some googling suggests that "pci-bridge" is the correct one.  At least
PPC-based Apple machines are using this.  See question "How do I boot
from a device attached to a PCI card" here:
	http://www.netbsd.org/ports/macppc/faq.html

So lets change qemu to use "pci-bridge" too.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/pci/pci.c

@@ -1330,7 +1330,7 @@ static const pci_class_desc pci_class_descriptions[] =
     { 0x0601, "ISA bridge", "isa"},
     { 0x0602, "EISA bridge", "eisa"},
     { 0x0603, "MC bridge", "mca"},
-    { 0x0604, "PCI bridge", "pci"},
+    { 0x0604, "PCI bridge", "pci-bridge"},
     { 0x0605, "PCMCIA bridge", "pcmcia"},
     { 0x0606, "NUBUS bridge", "nubus"},
     { 0x0607, "CARDBUS bridge", "cardbus"},