target/riscv: rvv-1.0: whole register move instructions

target/riscv: rvv-1.0: whole register move instructions

Add the following instructions:

* vmv1r.v
* vmv2r.v
* vmv4r.v
* vmv8r.v

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-40-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>