build: Suggest to download supported tinycbor

build: Suggest to download supported tinycbor

Note this patch is appropriate for release versions (or branches)
 while master or development branches can follow upstream's master branch
 and eventually synched when needed.

Bug: https://jira.iotivity.org/browse/IOT-1600
Change-Id: I361a75fa9dd52739dce0daa8e14333c95e6c9284
Origin: https://gerrit.iotivity.org/gerrit/#/c/14763/
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14763
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>