hw/i386/acpi: Add object_resolve_type_unambiguous to improve modularity

hw/i386/acpi: Add object_resolve_type_unambiguous to improve modularity

When building with CONFIG_Q35=n, we get:

    LINK    x86_64-softmmu/qemu-system-x86_64
  /usr/bin/ld: hw/i386/acpi-build.o: in function `acpi_get_misc_info':
  /source/qemu/hw/i386/acpi-build.c:243: undefined reference to `ich9_lpc_find'
  collect2: error: ld returned 1 exit status
  make[1]: *** [Makefile:204: qemu-system-x86_64] Error 1

This is due to a dependency in acpi-build.c on the ICH9_LPC
(via ich9_lpc_find) and PIIX4_PM (via piix4_pm_find) devices.

To allow better modularity (compile acpi-build.c with only
Q35/ICH9 or ISAPC/PIIX4), refactor the similar helper as
object_resolve_type_unambiguous(). This way we relax the
linker dependencies and can build the x86 targets with a
selection of machines (instead of all of them).

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190427144025.22880-3-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>