force enable DO_CUMULATE

force enable DO_CUMULATE

We can't use cumulative install because we don't use %suse_version macro.
However, our build system is based on openSUSE Build service and we use
always newer suse version than 1220. Thus, we can always enable cumulative
install instead of defining the suse_version. I think it's better than
we touch the suse_version macro manually.[1]

[1]: https://review.tizen.org/gerrit/#/c/25292/

Change-Id: I7673db1660945bb80e8c49a183b76927ae340e45
Signed-off-by: Chanho Park <chanho61.park@samsung.com>