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.

ref: https://review.tizen.org/gerrit/c/platform/upstream/build/+/25635/

Test result

* pre condition
gbs build -A armv7l
download dependency to cache

* set DO_CUMULATE=
* 1st
sudo rm -rf /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.*
gbs build -A armv7l
[  137s] [537/537] installing ecore-imf-evas-devel-1.25.1-201.5
[  138s] removing nis flags from /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.0/etc/nsswitch.conf..

* 2nd
sudo rm -rf /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.*
gbs build -A armv7l
[  137s] [537/537] installing ecore-imf-evas-devel-1.25.1-201.5
[  138s] removing nis flags from /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.0/etc/nsswitch.conf..

* set DO_CUMULATE=true
* 1st
sudo rm -rf /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.*
gbs build -A armv7l
[   99s] Running alarm-server %posttrans script
[   99s] removing nis flags from /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.0/etc/nsswitch.conf...

* 2nd
sudo rm -rf /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.*
gbs build -A armv7l
[   99s] Running alarm-server %posttrans script
[  100s] removing nis flags from /home/hglee/GBS-ROOT/t65std/local/BUILD-ROOTS/scratch.armv7l.0/etc/nsswitch.conf...

* 138s -> 100s (ratio 72%)

Change-Id: I904e73ea7eaa23b7e52a5011a558f103128d6eee
Signed-off-by: Hyunggi Lee <hyunggi.lee@samsung.com>