As for compiling syscalls.S needed syscall-aux.h header,
which is linked with making $(sys-asm-types), add it to deps.

Fixes:
> In file included from compel/arch/aarch64/plugins/std/syscalls/syscalls.S:2:0:
>     compel/include/uapi/compel/plugins/std/syscall-codes.h:568:44: fatal error: compel/plugins/std/syscall-aux.h: No such file or directory
>      #include <compel/plugins/std/syscall-aux.h>
>                                                 ^
>     compilation terminated.

Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>