target/riscv/kvm: handle the exit with debug reason

target/riscv/kvm: handle the exit with debug reason

If the breakpoint belongs to the userspace then set the ret value.

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240606014501.20763-3-duchao@eswincomputing.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>