Impact: cleaup
Make the following cleanups.
* There isn't much arch-specific about PERCPU_MODULE_RESERVE. Always
define it whether arch overrides PERCPU_ENOUGH_ROOM or not.
* blackfin overrides PERCPU_ENOUGH_ROOM to align static area size. Do
it by default.
* percpu allocation sizes doesn't have much to do with the page size.
Don't use PAGE_SHIFT in their definition.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>