syscalls: remove obsolete __IGNORE_ macros

These are all for ignoring the lack of obsolete system calls,
which have been marked the same way in scripts/checksyscall.sh,
so these can be removed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>