pc: acpi: isolate FADT specific data into AcpiFadtData structure

pc: acpi: isolate FADT specific data into AcpiFadtData structure

move FADT data initialization out of fadt_setup() into dedicated
init_fadt_data() that will set common for pc/q35 values in
AcpiFadtData structure and acpi_get_pm_info() will complement
it with pc/q35 specific values initialization.

That will allow to get rid of fadt_setup() and generalize
build_fadt() so it could be easily extended for rev5 and
reused by ARM target.

While at it also move facs/dsdt/xdsdt offsets from build_fadt()
arg list into AcpiFadtData, as they belong to the same dataset.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>