LoongArch: Check for AMO instructions in insns_not_supported()

Like llsc instructions, the atomic memory access instructions shouldn't
be supported for probing, so check for them in insns_not_supported().

Closes: https://lore.kernel.org/all/SY4P282MB351877A70A0333C790FE85A5C09C9@SY4P282MB3518.AUSP282.PROD.OUTLOOK.COM/
Tested-by: Jeff Xie <xiehuan09@gmail.com>
Reported-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>