Updated NSProvider structure for multi connections.

Updated NSProvider structure for multi connections.

NSProvider can have a only UDP connection information.
But cloud notification service scenraio need to multiple connection informations.
So NSProvider struct is updated for multi connection information.

NSProviderConnectionInfo is added at NSProvider.
NAProviderConnectionInfo is list of Provider connection infomation.
Mutex is added at NSInvokeRequest().

Change-Id: Ie83527e264f93a2f5839417a61997fcdcf541a87
Signed-off-by: KIM JungYong <jyong2.kim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/9275
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Tested-by: Uze Choi <uzchoi@samsung.com>