clockchips: Add FEAT_PERCPU clockevent flag

Add the flag CLOCK_EVT_FEAT_PERCPU which is supposed to be set for per
cpu clockevent devices.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: 3713c0cfd06fa49729a12929a7ee8b7ad48f3c02
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>