target/riscv: Set instance_align on RISCVCPU TypeInfo

Fix alignment of CPURISCVState.vreg.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200916004638.2444147-6-richard.henderson@linaro.org>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

target/riscv/cpu.c

@@ -628,6 +628,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
         .name = TYPE_RISCV_CPU,
         .parent = TYPE_CPU,
         .instance_size = sizeof(RISCVCPU),
+        .instance_align = __alignof__(RISCVCPU),
         .instance_init = riscv_cpu_init,
         .abstract = true,
         .class_size = sizeof(RISCVCPUClass),