pc: acpi: merge SSDT into DSDT

pc: acpi: merge SSDT into DSDT

Since both tables are built dynamically now,
there is no point in keeping ASL in them in separate
tables.
So do the same as we do for ARM where we have only
DSDT table, i.e. move SSDT ASL into DSDT and
drop SSDT altogether.
This patch doesn't change moved SSDT ASL in any way,
but it opens a way to relatively independently simplify
generated ASL on per device/subsystem basis in
followup series.
It also simplifies bios-tables-test where expected
SSDT blobs could be dropped and only DSDT ones
have to be maintained.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>