compat: restore timerfd settime and gettime compat syscalls

Both compat syscalls got lost with 9d94b9e2 "switch timerfd compat syscalls
to COMPAT_SYSCALL_DEFINE" because of a typo:
COMPAT instead of CONFIG_COMPAT.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>