linux-yocto/4.1: Always Running Timer Support

linux-yocto/4.1: Always Running Timer Support

Backporting mainline patches to add always running timer support (ART).

The main advantage of ART is that ART can be captured
simultaneous to the capture of audio and network device clocks,
allowing a correlation between timebases to be constructed.

   Arnd Bergmann (1):
     ntp/pps: replace getnstime_raw_and_real with 64-bit version

   Christopher S. Hall (4):
     time: Add cycles to nanoseconds translation
     time: Add timekeeping snapshot code capturing system time and counter
     time: Add driver cross timestamp interface for higher precision time synchronization
     x86/tsc: Always Running Timer (ART) correlated clocksource

   DengChao (1):
     timekeeping: Provide internal function __ktime_get_real_seconds

Signed-off-by: Yong, Jonathan <jonathan.yong@intel.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>