The argument for auditpipe(4)'s `AUDITPIPE_GET_PRESELECT_AUID` request is a data structure of type `struct auditpipe_ioctl_preselect` whose fields are not defined within the same header file. i.e `security/audit/audit_ioctl.h`
Here:
```
struct auditpipe_ioctl_preselect {
au_id_t aip_auid;
au_mask_t aip_mask;
};
```
has the data types `au_id_t` and `au_mask_t` whose definitions are present in `bsm/audit.h`. So it would be appropriate to move the definitions there and include `bsm/audit.h` within `security/audit/audit_ioctl.h`
Also, added a typedef alias for `struct auditpipe_ioctl_preselect` to enable easier use case within auditpipe's ioctl arguments.