Update C API doxygen
Update C API doxygen

C API description is updated for some fields such as subControllability.

Change-Id: Ie44c213657a9ffdd55ec386e8bc953bad709432d
Signed-off-by: ch79.cho <b32a386441682bfbcf78768049c86636501c53fa@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/13075
Tested-by: jenkins-iotivity <09cb29e8a2b473a2c978382eec13ee06fa017bda@opendaylight.org>
Reviewed-by: Uze Choi <3a26c91d8a4a3c9e246e43339f4782bb2483aece@samsung.com>

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