hw/i386/acpi-build: Introduce build_append_pcihp_resources() helper

hw/i386/acpi-build: Introduce build_append_pcihp_resources() helper

Extract the code that reserves resources for ACPI PCI hotplug
into a new helper named build_append_pcihp_resources() and
move it to pcihp.c. We will reuse it on ARM.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Message-Id: <20250714080639.2525563-12-eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>