target/riscv: Add defines for AIA CSRs

target/riscv: Add defines for AIA CSRs

The RISC-V AIA specification extends RISC-V local interrupts and
introduces new CSRs. This patch adds defines for the new AIA CSRs.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-8-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>