compat: Move compat_timespec/ timeval to compat_time.h
All the current architecture specific defines for these
are the same. Refactor these common defines to a common
header file.
The new common linux/compat_time.h is also useful as it
will eventually be used to hold all the defines that
are needed for compat time types that support non y2038
safe types. New architectures need not have to define these
new types as they will only use new y2038 safe syscalls.
This file can be deleted after y2038 when we stop supporting
non y2038 safe syscalls.