target/riscv: enable riscv kvm accel

target/riscv: enable riscv kvm accel

Add riscv kvm support in meson.build file.

Signed-off-by: Yifei Jiang <[email protected]>
Signed-off-by: Mingwang Li <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Message-id: 20220112081329[email protected]
Signed-off-by: Alistair Francis <[email protected]>