Modify the OxM callback implementation to select the appropriate cipher suite

Modify the OxM callback implementation to select the appropriate cipher suite
for creating secure session

[NOTE] I will modify the tinyDTLS cipher suite selection and enable/disable mechanism
       according to comments of https://gerrit.iotivity.org/gerrit/#/c/2456/

[Patch #1] Intial upload
[Patch #2] Modify the comment according to doxygen format.
[Patch #3] Modify the oxmjustworks.c according to comment.

Change-Id: I6fb555d486f21f3851a7f2da9964381863128240
Signed-off-by: leechul <chuls.lee@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/3351
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Woochul Shim <woochul.shim@samsung.com>
Reviewed-by: Sachin Agrawal <sachin.agrawal@intel.com>