arm: Allow SCHED_HRTICK on ARM

 * Upstream change. Improves performance since we have a working
   high resolution timer.

Change-Id: I84f2100a943f166085ee03f30eda1baa48428b04
m7: update defconfig

Change-Id: I5ee77170e0b6a4c2ba4ea18927489a793f93879b
Signed-off-by: Whitehawkx <xxwhitehawk@gmail.com>