time: Change posix clocks ops interfaces to use timespec64

struct timespec is not y2038 safe on 32 bit machines.

The posix clocks apis use struct timespec directly and through struct
itimerspec.

Replace the posix clock interfaces to use struct timespec64 and struct
itimerspec64 instead.  Also fix up their implementations accordingly.

Note that the clock_getres() interface has also been changed to use
timespec64 even though this particular interface is not affected by the
y2038 problem. This helps verification for internal kernel code for y2038
readiness by getting rid of time_t/ timeval/ timespec.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: arnd@arndb.de
Cc: y2038@lists.linaro.org
Cc: netdev@vger.kernel.org
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: john.stultz@linaro.org
Link: http://lkml.kernel.org/r/1490555058-4603-3-git-send-email-deepa.kernel@gmail.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>