ncs_samples work on ncs v2.3.0

ncs samples support ncs v2.2.0 now

all samples work in ncs v2.0.0

Only support ncs v1.9.x

Remove other ncs versions support. If you need to test ncs versions
less than ncs v1.9.0, check out tag: v1.5_v1.9 first and read README.rst
Bascially what you need to do is to change prj.conf to support versions
less than v1.9.0.

Supports ncs versions: v1.5.x/v1.6.x/v1.7.x/v1.8.x/v1.9.x

To work with a specified NCS tag, read prj.conf carefully.
Open the configurations relating to the specified version
and close the configurations of other versions.
Search NCS in prj.conf to locate the configurations quickly.

Supports ncs versions: v1.5.x/v1.6.x/v1.7.x/v1.8.x/v1.9.x

To work with a specified NCS tag, read prj.conf carefully.
Open the configurations relating to the specified version
and close the configurations of other versions.
Search NCS in prj.conf to locate the configurations quickly.