seccomp: add rules for specified architecture only

seccomp: add rules for specified architecture only

If the architecture is specified in the seccomp configuration, like:
```
2
whitelist errno 1
[x86_64]
accept allow
accept4 allow
```
We shoud add rules only for amd64 instead of add rules for
x32/i386/amd64.

1. If the [arch] was not specified in seccomp config, add seccomp rules
for all all compat architectures.
2. If the [arch] specified in seccomp config irrelevant to native host
arch, the rules will be ignored.
3. If specified [all] in seccomp config, add seccomp rules for all
compat architectures.
4. If specified [arch] as same as native host arch, add seccomp rules
for the native host arch.
5. If specified [arch] was not native host arch, but compat to host
arch, add seccomp rules for the specified arch only, NOT add seccomp
rules for native arch.

Signed-off-by: LiFeng <lifeng68@huawei.com>