clocksource: Add new feature flag CLOCK_SOURCE_SUSPEND_NONSTOP

Some x86 processors have a TSC clocksource, which continues to run
even
when system is suspended. Also most OMAP platforms have a
32 KHz timer
which has similar capability. Add a feature flag so that
it could be
utilized.

CRs-fixed: 536881
Change-Id:
I863678fec5a3021158240f2c5b144c552ba0b16a
Signed-off-by: Feng Tang
<feng.tang@intel.com>
Signed-off-by: John Stultz
<john.stultz@linaro.org>
Git-repo:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit:
5caf463
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

idea is
taken here -
https://github.com/jrior001/android_kernel_samsung_d2/commit/13f57f631867078ea02a406c6c9b3355de8a41dd