hw/acpi: Make ACPI IO address space configurable

hw/acpi: Make ACPI IO address space configurable

This is in preparation for adding support for ARM64 platforms
where it doesn't use port mapped IO for ACPI IO space. We are
making changes so that MMIO region can be accommodated
and board can pass the base address into the aml build function.

Also move few MEMORY_* definitions to header so that other memory
hotplug event signalling mechanisms (eg. Generic Event Device on
HW-reduced acpi platforms) can use the same from their respective
event handler code.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20190918130633.4872-2-shameerali.kolothum.thodi@huawei.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>