Convert monitor over to use virDomainDeviceAddress

Convert monitor over to use virDomainDeviceAddress

Convert the QEMU monitor APIs over to use virDomainDeviceAddress
structs for passing addresses in/out, instead of individual bits.
This makes the number of parameters smaller & easier to deal with.
No functional change

* src/qemu/qemu_driver.c, src/qemu/qemu_monitor.c,
  src/qemu/qemu_monitor.h, src/qemu/qemu_monitor_text.c,
  src/qemu/qemu_monitor_text.h: Change monitor hotplug APIs to
  take an explicit address ptr for all host/guest addresses