target/riscv: Use gen_shift_imm_fn for slli_uw

target/riscv: Use gen_shift_imm_fn for slli_uw

Always use tcg_gen_deposit_z_tl; the special case for
shamt >= 32 is handled there.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210823195529.560295-21-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>