bits/time.h: sync with glibc 2.16

CLOCK_MONOTONIC_RAW is available since 2.6.28
(2d42244ae71d: clocksource: introduce CLOCK_MONOTONIC_RAW), and
CLOCK_*_COARSE since 2.6.32 (da15cfdae033: time: Introduce
CLOCK_REALTIME_COARSE).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
bits/time.h: sync with latest glibc

Signed-off-by: Mike Frysinger <vapier@gentoo.org>