build: Add ES NS paths to pkg-config
build: Add ES NS paths to pkg-config

Public easy-setup and notification headers,
are copied in 2 level depths directory.

Change-Id: I7c9fd3a4bd1143c5ea05e7902292af23cf5e8934
Signed-off-by: Philippe Coval <ff46fec9739d31cce915aabcc3a7a2c00eee4d6c@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/16455
Tested-by: jenkins-iotivity <09cb29e8a2b473a2c978382eec13ee06fa017bda@opendaylight.org>
Reviewed-by: Uze Choi <3a26c91d8a4a3c9e246e43339f4782bb2483aece@samsung.com>

iotivity/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity