target/riscv: modification of the trans_csrxx for 128-bit support

target/riscv: modification of the trans_csrxx for 128-bit support

As opposed to the gen_arith and gen_shift generation helpers, the csr insns
do not have a common prototype, so the choice to generate 32/64 or 128-bit
helper calls is done in the trans_csrxx functions.

Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-18-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>