tests/acpi: Add empty ACPI data files for RISC-V

tests/acpi: Add empty ACPI data files for RISC-V

As per process documented (steps 1-3) in bios-tables-test.c, add empty
AML data files for RISC-V ACPI tables and add the entries in
bios-tables-test-allowed-diff.h.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20240716144306.2432257-8-sunilvl@ventanamicro.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>