Modify the SRMRequestHandler to use the CAEndpoint_t's infomation

Modify the SRMRequestHandler to use the CAEndpoint_t's infomation
for identify a secure channel connection.

Change-Id: I91caf27ba7b08ee69623a960bb8df4da0acfefd9
Signed-off-by: Chul Lee <chuls.lee@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/13809
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Joonghwan Lee <jh05.lee@samsung.com>
Reviewed-by: Randeep Singh <randeep.s@samsung.com>
(cherry picked from commit b321d908218d5c2fdf1807b47c9da0c85bdbefa5)
Reviewed-on: https://gerrit.iotivity.org/gerrit/14823
Reviewed-by: Kevin Kane <kkane@microsoft.com>