qtest/riscv-iommu-test: add init queues test

qtest/riscv-iommu-test: add init queues test

Add an additional test to further exercise the IOMMU where we attempt to
initialize the command, fault and page-request queues.

These steps are taken from chapter 6.2 of the RISC-V IOMMU spec,
"Guidelines for initialization". It emulates what we expect from the
software/OS when initializing the IOMMU.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241016204038.649340-12-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>