proc: stats: Use arch_idle_time for idle and iowait times if available
proc: stats: Use arch_idle_time for idle and iowait times if available

Git commit a25cac5198d4ff28 "proc: Consider NO_HZ when printing idle and
iowait times" changes the code for /proc/stat to use get_cpu_idle_time_us
and get_cpu_iowait_time_us if the system is running with nohz enabled.
For architectures which define arch_idle_time (currently s390 only)
this is a change for the worse. The result of arch_idle_time is supposed
to be the exact sleep time of the target cpu and should be used instead
of the value kept by the scheduler.

Signed-off-by: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>
Reviewed-by: Michal Hocko <829500b200af6c2a0eca4dfd5c388e6b8fbe8dc6@suse.cz>
Reviewed-by: Srivatsa S. Bhat <5b23f8226e886b22344fc642373ea657dd596b63@linux.vnet.ibm.com>
Link: 37718cac3dcf4a30a830945f0681d3e97922a8de@de.ibm.com
Signed-off-by: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas