target/riscv: Relax fld alignment requirement

target/riscv: Relax fld alignment requirement

According to the risc-v specification:
"FLD and FSD are only guaranteed to execute atomically if the effective
address is naturally aligned and XLEN≥64."

We currently implement fld as MO_ATOM_IFALIGN when XLEN < 64, which does
not violate the rules. But it will hide some problems. So relax it to
MO_ATOM_NONE.

Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240802072417.659-4-zhiwei_liu@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>