pci: fix PCI resource reserve capability on BE

pci: fix PCI resource reserve capability on BE

PCI resource reserve capability should use LE format as all other PCI
things. If we don't then seabios won't boot:

=== PCI new allocation pass #1 ===
PCI: check devices
PCI: QEMU resource reserve cap: size 10000000000000 type io
PCI: secondary bus 1 size 10000000000000 type io
PCI: secondary bus 1 size 00200000 type mem
PCI: secondary bus 1 size 00200000 type prefmem
=== PCI new allocation pass #2 ===
PCI: out of I/O address space

This became more important since we started reserving IO by default,
previously no one noticed.

Fixes: e2a6290aab ("hw/pcie-root-port: Fix hotplug for PCI devices requiring IO")
Cc: marcel.apfelbaum@gmail.com
Fixes: 226263fb5c ("hw/pci: add QEMU-specific PCI capability to the Generic PCI Express Root Port")
Cc: zuban32s@gmail.com
Fixes: 6755e618d0 ("hw/pci: add PCI resource reserve capability to legacy PCI bridge")
Cc: jing2.liu@linux.intel.com
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>