powerpc: Enable seccomp architecture tracking

stable inclusion
from stable-5.11-rc1
commit e7bcb462
bugzilla: 167382
CVE: N/A

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e7bcb4622ddf4473da6c03fa8423919a568c57dc



-------------------------------------------------

To enable seccomp constant action bitmaps, we need to have a static
mapping to the audit architecture and system call table size. Add these
for powerpc.

__LITTLE_ENDIAN__ is used here instead of CONFIG_CPU_LITTLE_ENDIAN
to keep it consistent with asm/syscall.h.

Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/0b64925362671cdaa26d01bfe50b3ba5e164adfd.1605101222.git.yifeifz2@illinois.edu


Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>