[IOT-1511] Update mbedTLS to use 2.4.0 release tagged version

[IOT-1511] Update mbedTLS to use 2.4.0 release tagged version

Reviewed-on: https://gerrit.iotivity.org/gerrit/13973
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: David Antler <david.a.antler@intel.com>
Reviewed-by: Habib Virji <habib.virji@samsung.com>
Reviewed-by: Oleksandr Dmytrenko <o.dmytrenko@samsung.com>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
This change also includes the fix:

Fix mbedtls-2.4.0 build error

.git/refs/tags directory is empty

Reviewed-on: https://gerrit.iotivity.org/gerrit/14223
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Kevin Kane <kkane@microsoft.com>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-by: Chul Lee <chuls.lee@samsung.com>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Change-Id: I259709cd2024eb9eca83aa19c90783bc2a9f8c72
Signed-off-by: Kevin Kane <kkane@microsoft.com>
Signed-off-by: Dmitriy Zhuravlev <d.zhuravlev@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14195
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>