docs/specs: add RISC-V CPU Debug support info

Add documentation regarding how QEMU handles Debug versions 0.13 and
1.0.

Signed-off-by: Daniel Henrique Barboza <daniel.barboza@oss.qualcomm.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20260805182506.2943757-6-daniel.barboza@oss.qualcomm.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2 files changed