target/riscv: Update CSR bits name for svadu extension

target/riscv: Update CSR bits name for svadu extension

The Svadu specification updated the name of the *envcfg bit from
HADE to ADUE.

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20230816141916.66898-1-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>