Add iotivity.pc.in file and generate iotivity.pc file

Add iotivity.pc.in file and generate iotivity.pc file

This patch addresses the second part of IOT-524. The current
changes include adding a new iotivity.pc.in file and generating
the iotivity.pc file using .pc.in file.

Making the relevant changes in gbsbuild.sh files to include iotivity.pc.in
file during tizen builds.

Change-Id: Ie3ed7ccdf6e29d427362d0bb2b85439508997b6b
Signed-off-by: Ravi Nanjundappa <nravi.n@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2378
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>